Merge latest patches from upstream am: fdad07cb6e am: 771b6d93c6 am: 6c1bd82791

Original change: https://android-review.googlesource.com/c/platform/external/libchrome-gestures/+/2480579

Change-Id: I0051830c62d5e48b3723663d5e3aebd5ac7f876b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

24 files changed, 337 insertions, 355 deletions

diff --git a/Android.bp b/Android.bp
index eb7d8ac..8be85fa 100644
--- a/Android.bp
+++ b/Android.bp
@@ -132,7 +132,6 @@ cc_test {
         "src/immediate_interpreter_unittest.cc",
         "src/integral_gesture_filter_interpreter_unittest.cc",
         "src/interpreter_unittest.cc",
-        "src/list_unittest.cc",
         "src/logging_filter_interpreter_unittest.cc",
         "src/lookahead_filter_interpreter_unittest.cc",
         "src/mouse_interpreter_unittest.cc",
diff --git a/METADATA.android b/METADATA.android
index 00233ca..4aee07c 100644
--- a/METADATA.android
+++ b/METADATA.android
@@ -6,7 +6,7 @@ third_party {
     type: GIT
     value: "https://chromium.googlesource.com/chromiumos/platform/gestures/"
   }
-  version: "3059225019e295de1138574a16c0102c6845fefb"
-  last_upgrade_date { year: 2023 month: 02 day: 27  }
+  version: "2a80cba49fb09f6f2632b61f21ea7dc62acd82d7"
+  last_upgrade_date { year: 2023 month: 03 day: 10  }
   license_type: NOTICE
 }
diff --git a/Makefile b/Makefile
index c6165e9..d04ce98 100644
--- a/Makefile
+++ b/Makefile
@@ -60,7 +60,6 @@ TEST_OBJECTS=\
 	$(OBJDIR)/immediate_interpreter_unittest.o \
 	$(OBJDIR)/integral_gesture_filter_interpreter_unittest.o \
 	$(OBJDIR)/interpreter_unittest.o \
-	$(OBJDIR)/list_unittest.o \
 	$(OBJDIR)/logging_filter_interpreter_unittest.o \
 	$(OBJDIR)/lookahead_filter_interpreter_unittest.o \
 	$(OBJDIR)/non_linearity_filter_interpreter_unittest.o \
@@ -112,7 +111,7 @@ DESTDIR = .
 
 CXXFLAGS+=\
 	-g \
-	-std=gnu++11 \
+	-std=gnu++17 \
 	-fno-exceptions \
 	-fno-strict-aliasing \
 	-fPIC \
diff --git a/include/gestures.h b/include/gestures.h
index e4f7cc2..f21d531 100644
--- a/include/gestures.h
+++ b/include/gestures.h
@@ -55,7 +55,8 @@ struct HardwareProperties {
   float right;
   // The maximum Y coordinate that the device can report.
   float bottom;
-  // The resolutions of the X and Y axes, in units per mm.
+  // The resolutions of the X and Y axes, in units per mm. Set to 0 if the
+  // resolution is unknown.
   float res_x;
   float res_y;
 
diff --git a/include/list.h b/include/list.h
index d5d94c4..c822e7a 100644
--- a/include/list.h
+++ b/include/list.h
@@ -5,104 +5,27 @@
 #ifndef GESTURES_LIST_H__
 #define GESTURES_LIST_H__
 
+#include <list>
 #include "include/logging.h"
 #include "include/memory_manager.h"
 
 namespace gestures {
 
-// Elt must have the following members:
-// Elt* next_;
-// Elt* prev_;
-
-template<typename Elt>
-class List {
- public:
-  List() { Init(); }
-  ~List() { DeleteAll(); }
-
-  // inserts new_elt before existing. Assumes existing is in list already.
-  void InsertBefore(Elt *existing, Elt* new_elt) {
-    size_++;
-    Elt* pre_new = existing->prev_;
-    pre_new->next_ = new_elt;
-    new_elt->prev_ = pre_new;
-    new_elt->next_ = existing;
-    existing->prev_ = new_elt;
-  }
-
-  Elt* Unlink(Elt* existing) {
-    if (Empty()) {
-      Err("Can't pop from empty list!");
-      return NULL;
-    }
-    size_--;
-    existing->prev_->next_ = existing->next_;
-    existing->next_->prev_ = existing->prev_;
-    existing->prev_ = existing->next_ = NULL;
-    return existing;
-  }
-
-  void PushFront(Elt* elt) { InsertBefore(sentinel_.next_, elt); }
-  Elt* PopFront() { return Unlink(sentinel_.next_); }
-  void PushBack(Elt* elt) { InsertBefore(&sentinel_, elt); }
-  Elt* PopBack() { return Unlink(sentinel_.prev_); }
-
-  virtual void DeleteAll() {
-    while (!Empty())
-      delete PopFront();
-  }
-
-  Elt* Head() const { return sentinel_.next_; }
-  Elt* Tail() const { return sentinel_.prev_; }
-  size_t size() const { return size_; }
-  bool Empty() const { return size() == 0; }
-
-  // Iterator-like methods
-  Elt* Begin() const { return Head(); }
-  Elt* End() const { return const_cast<Elt*>(&sentinel_); }
-
-  void Init() {
-    size_ = 0;
-    sentinel_.next_ = sentinel_.prev_ = &sentinel_;
-  }
-
- private:
-  // sentinel element
-  Elt sentinel_;
-
-  size_t size_;
-};
-
-
 template<typename Elt>
-class MemoryManagedList : public List<Elt> {
+class MemoryManagedList : public std::list<Elt*> {
  public:
-  using List<Elt>::Empty;
-  using List<Elt>::PopBack;
-  using List<Elt>::PopFront;
-  using List<Elt>::PushBack;
-  using List<Elt>::PushFront;
-
   MemoryManagedList() { };
-  ~MemoryManagedList() { DeleteAll(); }
+  ~MemoryManagedList() { clear(); }
 
   void Init(MemoryManager<Elt>* memory_manager) {
     memory_manager_ = memory_manager;
-    List<Elt>::Init();
-  }
-
-  Elt* NewElt() {
-    Elt* elt = memory_manager_->Allocate();
-    AssertWithReturnValue(elt, NULL);
-    elt->next_ = elt->prev_ = NULL;
-    return elt;
   }
 
   Elt* PushNewEltBack() {
     AssertWithReturnValue(memory_manager_, NULL);
     Elt* elt = NewElt();
     AssertWithReturnValue(elt, NULL);
-    PushBack(elt);
+    this->push_back(elt);
     return elt;
   }
 
@@ -110,26 +33,35 @@ class MemoryManagedList : public List<Elt> {
     AssertWithReturnValue(memory_manager_, NULL);
     Elt* elt = NewElt();
     AssertWithReturnValue(elt, NULL);
-    PushFront(elt);
+    this->push_front(elt);
     return elt;
   }
 
   void DeleteFront() {
     AssertWithReturn(memory_manager_);
-    memory_manager_->Free(PopFront());
+    memory_manager_->Free(this->front());
+    this->pop_front();
   }
 
   void DeleteBack() {
     AssertWithReturn(memory_manager_);
-    memory_manager_->Free(PopBack());
+    memory_manager_->Free(this->pop_back());
   }
 
-  virtual void DeleteAll() {
-    while (!Empty())
+  void clear() {
+    while (!this->empty())
       DeleteFront();
   }
+
  private:
   MemoryManager<Elt>* memory_manager_;
+
+  Elt* NewElt() {
+    Elt* elt = memory_manager_->Allocate();
+    AssertWithReturnValue(elt, NULL);
+    elt->next_ = elt->prev_ = NULL;
+    return elt;
+  }
 };
 
 
diff --git a/include/lookahead_filter_interpreter.h b/include/lookahead_filter_interpreter.h
index 33dcc9b..31aefe4 100644
--- a/include/lookahead_filter_interpreter.h
+++ b/include/lookahead_filter_interpreter.h
@@ -3,15 +3,16 @@
 // found in the LICENSE file.
 
 #include <algorithm>
+#include <list>
 #include <map>
 #include <memory>
+#include <vector>
 
 #include <gtest/gtest.h>  // For FRIEND_TEST
 
 #include "include/filter_interpreter.h"
 #include "include/finger_metrics.h"
 #include "include/gestures.h"
-#include "include/list.h"
 #include "include/prop_registry.h"
 #include "include/tracer.h"
 
@@ -33,6 +34,8 @@ class LookaheadFilterInterpreter : public FilterInterpreter {
   FRIEND_TEST(LookaheadFilterInterpreterTest, SimpleTest);
   FRIEND_TEST(LookaheadFilterInterpreterTest, SpuriousCallbackTest);
   FRIEND_TEST(LookaheadFilterInterpreterTest, VariableDelayTest);
+  FRIEND_TEST(LookaheadFilterInterpreterTest, QStateListTest);
+
  public:
   LookaheadFilterInterpreter(PropRegistry* prop_reg, Interpreter* next,
                              Tracer* tracer);
@@ -108,8 +111,12 @@ class LookaheadFilterInterpreter : public FilterInterpreter {
 
   stime_t ExtraVariableDelay() const;
 
-  List<QState> queue_;
-  List<QState> free_list_;
+  class QStateList : public std::list<QState*> {
+  public:
+    QState* at(int offset);
+  } queue_;
+
+  std::vector<QState*> free_list_;
 
   // The last id assigned to a contact (part of drumroll suppression)
   short last_id_;
diff --git a/include/prop_registry.h b/include/prop_registry.h
index 836b98b..4545a33 100644
--- a/include/prop_registry.h
+++ b/include/prop_registry.h
@@ -46,9 +46,8 @@ class PropertyDelegate;
 
 class Property {
  public:
-  Property(PropRegistry* parent, const char* name,
-           PropertyDelegate* delegate)
-      : gprop_(NULL), parent_(parent), delegate_(delegate), name_(name) {}
+  Property(PropRegistry* parent, const char* name)
+      : parent_(parent), name_(name) {}
 
   virtual ~Property() {
     if (parent_)
@@ -59,18 +58,9 @@ class Property {
   virtual void CreatePropImpl() = 0;
   void DestroyProp();
 
-  // b/253585974
-  // delegate used to get passed as a constructor parameter but that
-  // led to a chance that the delegate was 'this' and setting the
-  // delegate to 'this' in the initializer list allowed the property
-  // creation to use 'this' before it was initialized.  This could
-  // lead to unexpected behavior and if you were lucky to a crash.
-  //
-  // Now the delegate is always NULL on initilization of the property
-  // instance and after the delegate and property are completely
-  // created the user should set the delegate in the constructor
-  // body. This will allow access to this in a safe manner.
-  void SetDelegate(PropertyDelegate* delegate);
+  void SetDelegate(PropertyDelegate* delegate) {
+    delegate_ = delegate;
+  }
 
   const char* name() { return name_; }
   // Returns a newly allocated Value object
@@ -91,9 +81,9 @@ class Property {
   virtual void HandleGesturesPropWritten() = 0;
 
  protected:
-  GesturesProp* gprop_;
+  GesturesProp* gprop_ = NULL;
   PropRegistry* parent_;
-  PropertyDelegate* delegate_;
+  PropertyDelegate* delegate_ = NULL;
 
  private:
   const char* name_;
@@ -101,9 +91,8 @@ class Property {
 
 class BoolProperty : public Property {
  public:
-  BoolProperty(PropRegistry* reg, const char* name, GesturesPropBool val,
-               PropertyDelegate* delegate = NULL)
-      : Property(reg, name, delegate), val_(val) {
+  BoolProperty(PropRegistry* reg, const char* name, GesturesPropBool val)
+      : Property(reg, name), val_(val) {
     if (parent_)
       parent_->Register(this);
   }
@@ -118,8 +107,8 @@ class BoolProperty : public Property {
 class BoolArrayProperty : public Property {
  public:
   BoolArrayProperty(PropRegistry* reg, const char* name, GesturesPropBool* vals,
-                    size_t count, PropertyDelegate* delegate = NULL)
-      : Property(reg, name, delegate), vals_(vals), count_(count) {
+                    size_t count)
+      : Property(reg, name), vals_(vals), count_(count) {
     if (parent_)
       parent_->Register(this);
   }
@@ -134,9 +123,8 @@ class BoolArrayProperty : public Property {
 
 class DoubleProperty : public Property {
  public:
-  DoubleProperty(PropRegistry* reg, const char* name, double val,
-                 PropertyDelegate* delegate = NULL)
-      : Property(reg, name, delegate), val_(val) {
+  DoubleProperty(PropRegistry* reg, const char* name, double val)
+      : Property(reg, name), val_(val) {
     if (parent_)
       parent_->Register(this);
   }
@@ -151,8 +139,8 @@ class DoubleProperty : public Property {
 class DoubleArrayProperty : public Property {
  public:
   DoubleArrayProperty(PropRegistry* reg, const char* name, double* vals,
-                      size_t count, PropertyDelegate* delegate = NULL)
-      : Property(reg, name, delegate), vals_(vals), count_(count) {
+                      size_t count)
+      : Property(reg, name), vals_(vals), count_(count) {
     if (parent_)
       parent_->Register(this);
   }
@@ -167,9 +155,8 @@ class DoubleArrayProperty : public Property {
 
 class IntProperty : public Property {
  public:
-  IntProperty(PropRegistry* reg, const char* name, int val,
-              PropertyDelegate* delegate = NULL)
-      : Property(reg, name, delegate), val_(val) {
+  IntProperty(PropRegistry* reg, const char* name, int val)
+      : Property(reg, name), val_(val) {
     if (parent_)
       parent_->Register(this);
   }
@@ -183,9 +170,9 @@ class IntProperty : public Property {
 
 class IntArrayProperty : public Property {
  public:
-  IntArrayProperty(PropRegistry* reg, const char* name, int* vals, size_t count,
-                   PropertyDelegate* delegate = NULL)
-      : Property(reg, name, delegate), vals_(vals), count_(count) {
+  IntArrayProperty(PropRegistry* reg, const char* name, int* vals,
+                   size_t count)
+      : Property(reg, name), vals_(vals), count_(count) {
     if (parent_)
       parent_->Register(this);
   }
@@ -200,9 +187,8 @@ class IntArrayProperty : public Property {
 
 class StringProperty : public Property {
  public:
-  StringProperty(PropRegistry* reg, const char* name, const char* val,
-                 PropertyDelegate* delegate = NULL)
-      : Property(reg, name, delegate), val_(val) {
+  StringProperty(PropRegistry* reg, const char* name, const char* val)
+      : Property(reg, name), val_(val) {
     if (parent_)
       parent_->Register(this);
   }
diff --git a/src/iir_filter_interpreter.cc b/src/iir_filter_interpreter.cc
index 0558ef6..042e0f5 100644
--- a/src/iir_filter_interpreter.cc
+++ b/src/iir_filter_interpreter.cc
@@ -41,6 +41,7 @@ IirFilterInterpreter::IirFilterInterpreter(PropRegistry* prop_reg,
       a2_(prop_reg, "IIR a2", 0.412801598096189),
       iir_dist_thresh_(prop_reg, "IIR Distance Threshold", 10),
       adjust_iir_on_warp_(prop_reg, "Adjust IIR History On Warp", false) {
+  InitName();
   b0_.SetDelegate(this);
   b1_.SetDelegate(this);
   b2_.SetDelegate(this);
@@ -48,7 +49,6 @@ IirFilterInterpreter::IirFilterInterpreter(PropRegistry* prop_reg,
   a1_.SetDelegate(this);
   a2_.SetDelegate(this);
   iir_dist_thresh_.SetDelegate(this);
-  InitName();
 }
 
 void IirFilterInterpreter::SyncInterpretImpl(HardwareState* hwstate,
diff --git a/src/immediate_interpreter.cc b/src/immediate_interpreter.cc
index 70369eb..7af423c 100644
--- a/src/immediate_interpreter.cc
+++ b/src/immediate_interpreter.cc
@@ -1095,7 +1095,7 @@ ImmediateInterpreter::ImmediateInterpreter(PropRegistry* prop_reg,
       keyboard_touched_timeval_high_(prop_reg, "Keyboard Touched Timeval High",
                                      0),
       keyboard_touched_timeval_low_(prop_reg, "Keyboard Touched Timeval Low",
-                                    0, this),
+                                    0),
       keyboard_palm_prevent_timeout_(prop_reg, "Keyboard Palm Prevent Timeout",
                                      0.5),
       motion_tap_prevent_timeout_(prop_reg, "Motion Tap Prevent Timeout",
@@ -1136,6 +1136,7 @@ ImmediateInterpreter::ImmediateInterpreter(PropRegistry* prop_reg,
       quick_acceleration_factor_(prop_reg, "Quick Acceleration Factor", 0.0) {
   InitName();
   requires_metrics_ = true;
+  keyboard_touched_timeval_low_.SetDelegate(this);
 }
 
 void ImmediateInterpreter::SyncInterpretImpl(HardwareState* hwstate,
diff --git a/src/list_unittest.cc b/src/list_unittest.cc
deleted file mode 100644
index 9c8ea74..0000000
--- a/src/list_unittest.cc
+++ /dev/null
@@ -1,93 +0,0 @@
-// Copyright 2011 The ChromiumOS Authors
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include <algorithm>
-#include <set>
-
-#include <gtest/gtest.h>
-
-#include "include/list.h"
-#include "include/util.h"
-
-namespace gestures {
-
-class ListTest : public ::testing::Test {};
-
-namespace {
-struct Node {
-  explicit Node() : val_(-1) {}
-  explicit Node(int val) : val_(val) {}
-  int val_;
-  Node* next_;
-  Node* prev_;
-};
-
-void VerifyList(List<Node>& list) {
-  Node* first = list.Head()->prev_;  // sentinel
-  Node* second = list.Head();  // next elt (sentinel or first element)
-  std::set<Node*> seen_nodes;
-  if (!list.Empty())
-    EXPECT_NE(first, second);
-  else
-    EXPECT_EQ(first, second);
-  seen_nodes.insert(second);
-  for (size_t i = 0; i <= list.size(); ++i) {
-    EXPECT_EQ(first->next_, second);
-    EXPECT_EQ(second->prev_, first);
-    if (i < list.size()) {
-      first = second;
-      second = second->next_;
-      EXPECT_FALSE(SetContainsValue(seen_nodes, second));
-      seen_nodes.insert(second);
-    }
-  }
-  EXPECT_EQ(seen_nodes.size(), list.size() + 1);
-  // second should now be sentinal tail
-  Node* sen_tail = list.Tail()->next_;
-  EXPECT_EQ(second, sen_tail);
-}
-}
-
-TEST(ListTest, SimpleTest) {
-  List<Node> list;
-  VerifyList(list);
-  EXPECT_TRUE(list.Empty());
-  EXPECT_EQ(0, list.size());
-  list.PushFront(new Node(4));
-  VerifyList(list);
-  EXPECT_FALSE(list.Empty());
-  EXPECT_EQ(1, list.size());
-  list.PushFront(new Node(5));
-  VerifyList(list);
-  EXPECT_EQ(2, list.size());
-  EXPECT_EQ(4, list.Tail()->val_);
-  EXPECT_EQ(5, list.Head()->val_);
-  list.PushBack(new Node(3));
-  VerifyList(list);
-  EXPECT_EQ(3, list.size());
-
-  Node* node = list.PopFront();
-  VerifyList(list);
-  ASSERT_TRUE(node);
-  EXPECT_EQ(5, node->val_);
-  delete node;
-
-  node = list.PopBack();
-  VerifyList(list);
-  ASSERT_TRUE(node);
-  EXPECT_EQ(3, node->val_);
-  delete node;
-
-  node = list.PopBack();
-  VerifyList(list);
-  ASSERT_TRUE(node);
-  EXPECT_EQ(4, node->val_);
-  delete node;
-
-  node = list.PopBack();
-  VerifyList(list);
-  EXPECT_EQ(NULL, node);
-}
-
-}  // namespace gestures
diff --git a/src/logging_filter_interpreter.cc b/src/logging_filter_interpreter.cc
index d504607..2c43238 100644
--- a/src/logging_filter_interpreter.cc
+++ b/src/logging_filter_interpreter.cc
@@ -17,15 +17,19 @@ LoggingFilterInterpreter::LoggingFilterInterpreter(PropRegistry* prop_reg,
                                                    Interpreter* next,
                                                    Tracer* tracer)
     : FilterInterpreter(prop_reg, next, tracer, true),
-      event_logging_enable_(prop_reg, "Event Logging Enable", false, this),
-      logging_notify_(prop_reg, "Logging Notify", 0, this),
-      logging_reset_(prop_reg, "Logging Reset", 0, this),
+      event_logging_enable_(prop_reg, "Event Logging Enable", false),
+      logging_notify_(prop_reg, "Logging Notify", 0),
+      logging_reset_(prop_reg, "Logging Reset", 0),
       log_location_(prop_reg, "Log Path",
                     "/var/log/xorg/touchpad_activity_log.txt"),
       integrated_touchpad_(prop_reg, "Integrated Touchpad", false) {
   InitName();
   if (prop_reg && log_.get())
     prop_reg->set_activity_log(log_.get());
+  event_logging_enable_.SetDelegate(this);
+  BoolWasWritten(&event_logging_enable_);
+  logging_notify_.SetDelegate(this);
+  logging_reset_.SetDelegate(this);
 }
 
 void LoggingFilterInterpreter::IntWasWritten(IntProperty* prop) {
diff --git a/src/lookahead_filter_interpreter.cc b/src/lookahead_filter_interpreter.cc
index f7abaf5..f60b0f5 100644
--- a/src/lookahead_filter_interpreter.cc
+++ b/src/lookahead_filter_interpreter.cc
@@ -19,9 +19,12 @@ namespace {
 static const stime_t kMaxDelay = 0.09;  // 90ms
 }
 
+static const size_t kMaxQNodes = 16;
+
 LookaheadFilterInterpreter::LookaheadFilterInterpreter(
     PropRegistry* prop_reg, Interpreter* next, Tracer* tracer)
     : FilterInterpreter(NULL, next, tracer, false),
+      free_list_(kMaxQNodes),
       last_id_(0), max_fingers_per_hwstate_(0), interpreter_due_(-1.0),
       last_interpreted_time_(-1.0),
       min_nonsuppress_speed_(prop_reg, "Input Queue Min Nonsuppression Speed",
@@ -46,40 +49,42 @@ LookaheadFilterInterpreter::LookaheadFilterInterpreter(
 void LookaheadFilterInterpreter::SyncInterpretImpl(HardwareState* hwstate,
                                                        stime_t* timeout) {
   // Push back into queue
-  if (free_list_.Empty()) {
+  if (free_list_.empty()) {
     Err("Can't accept new hwstate b/c we're out of nodes!");
     Err("Now: %f, interpreter_due_ %f", hwstate->timestamp, interpreter_due_);
     Err("Dump of queue:");
-    for (QState* it = queue_.Begin(); it != queue_.End(); it = it->next_)
-      Err("Due: %f%s", it->due_, it->completed_ ? " (c)" : "");
+    for (const auto& element : queue_)
+      Err("Due: %f%s", element->due_, element->completed_ ? " (c)" : "");
     return;
   }
-  QState* node = free_list_.PopFront();
+  QState* node = free_list_.back();
+  free_list_.pop_back();
   node->set_state(*hwstate);
   double delay = max(0.0, min<stime_t>(kMaxDelay, min_delay_.val_));
   node->due_ = hwstate->timestamp + delay;
   node->completed_ = false;
-  if (queue_.Empty())
+  if (queue_.empty())
     node->output_ids_.clear();
   else
-    node->output_ids_ = queue_.Tail()->output_ids_;
-  // At this point, if ExtraVariableDelay() > 0, queue_.Tail()->due_ may have
+    node->output_ids_ = queue_.back()->output_ids_;
+  // At this point, if ExtraVariableDelay() > 0, queue_.back()->due_ may have
   // ExtraVariableDelay() applied, but node->due_ does not, yet.
-  if (!queue_.Empty() &&
-      (queue_.Tail()->due_ - node->due_ > ExtraVariableDelay())) {
+  if (!queue_.empty() &&
+      (queue_.back()->due_ - node->due_ > ExtraVariableDelay())) {
     Err("Clock changed backwards. Flushing queue.");
     stime_t next_timeout = NO_DEADLINE;
-    QState* q_node = queue_.Head();
+    auto q_node_iter = queue_.begin();
     do {
-      if (!q_node->completed_)
-        next_->SyncInterpret(&q_node->state_, &next_timeout);
-      q_node = q_node->next_;
-      free_list_.PushBack(queue_.PopFront());
-    } while (!queue_.Empty());
+      if (!(*q_node_iter)->completed_)
+        next_->SyncInterpret(&(*q_node_iter)->state_, &next_timeout);
+      ++q_node_iter;
+      free_list_.push_back(queue_.front());
+      queue_.pop_front();
+    } while (!queue_.empty());
     interpreter_due_ = -1.0;
     last_interpreted_time_ = -1.0;
   }
-  queue_.PushBack(node);
+  queue_.push_back(node);
   AssignTrackingIds();
   AttemptInterpolation();
   UpdateInterpreterDue(interpreter_due_ < 0.0 ?
@@ -88,7 +93,7 @@ void LookaheadFilterInterpreter::SyncInterpretImpl(HardwareState* hwstate,
   HandleTimerImpl(hwstate->timestamp, timeout);
 
   // Copy finger flags for upstream filters.
-  QState* q_node = queue_.Head();
+  QState* q_node = queue_.front();
   if (q_node->state_.SameFingersAs(*hwstate)) {
     for (size_t i = 0; i < hwstate->finger_cnt; i++) {
       hwstate->fingers[i].flags = q_node->state_.fingers[i].flags;
@@ -143,7 +148,7 @@ void LookaheadFilterInterpreter::AssignTrackingIds() {
     // Always reassign trackingID on the very first hwstate so that
     // the next hwstate can inherit the trackingID mapping.
     if (queue_.size() == 1) {
-      QState* tail = queue_.Tail();
+      QState* tail = queue_.back();
       HardwareState* hs = &tail->state_;
       for (size_t i = 0; i < hs->finger_cnt; i++) {
         FingerState* fs = &hs->fingers[i];
@@ -156,11 +161,11 @@ void LookaheadFilterInterpreter::AssignTrackingIds() {
     return;
   }
 
-  QState* tail = queue_.Tail();
+  auto tail = queue_.at(-1);
   HardwareState* hs = &tail->state_;
-  QState* prev_qs = queue_.size() < 2 ? NULL : tail->prev_;
+  QState* prev_qs = queue_.size() < 2 ? NULL : queue_.at(-2);
   HardwareState* prev_hs = prev_qs ? &prev_qs->state_ : NULL;
-  QState* prev2_qs = queue_.size() < 3 ? NULL : prev_qs->prev_;
+  QState* prev2_qs = queue_.size() < 3 ? NULL : queue_.at(-3);
   HardwareState* prev2_hs = prev2_qs ? &prev2_qs->state_ : NULL;
 
   RemoveMissingIdsFromMap(&tail->output_ids_, *hs);
@@ -356,11 +361,12 @@ void LookaheadFilterInterpreter::TapDownOccurringGesture(stime_t now) {
     return;
   if (queue_.size() < 2)
     return;  // Not enough data to know
-  HardwareState& hs = queue_.Tail()->state_;
-  if (queue_.Tail()->state_.timestamp != now)
+  HardwareState& hs = queue_.back()->state_;
+  if (queue_.back()->state_.timestamp != now)
     return;  // We didn't push a new hardware state now
-  // See if latest hwstate has finger that previous doesn't
-  HardwareState& prev_hs = queue_.Tail()->prev_->state_;
+  // See if latest hwstate has finger that previous doesn't.
+  // Get the state_ of back->prev
+  HardwareState& prev_hs = queue_.at(-2)->state_;
   if (hs.finger_cnt > prev_hs.finger_cnt) {
     // Finger was added.
     ProduceGesture(Gesture(kGestureFling, prev_hs.timestamp, hs.timestamp,
@@ -396,18 +402,20 @@ short LookaheadFilterInterpreter::NextTrackingId() {
 void LookaheadFilterInterpreter::AttemptInterpolation() {
   if (queue_.size() < 2)
     return;
-  QState* new_node = queue_.Tail();
-  QState* prev = new_node->prev_;
+  QState* new_node = queue_.at(-1);
+  QState* prev = queue_.at(-2);
   if (new_node->state_.timestamp - prev->state_.timestamp <
-      split_min_period_.val_)
+      split_min_period_.val_) {
     return;  // Nodes came in too quickly to need interpolation
+  }
   if (!prev->state_.SameFingersAs(new_node->state_))
     return;
-  QState* node = free_list_.PopFront();
-  if (!node) {
+  if (free_list_.empty()) {
     Err("out of nodes?");
     return;
   }
+  QState* node = free_list_.back();
+  free_list_.pop_back();
   node->state_.fingers = node->fs_.get();
   node->completed_ = false;
   Interpolate(prev->state_, new_node->state_, &node->state_);
@@ -418,11 +426,10 @@ void LookaheadFilterInterpreter::AttemptInterpolation() {
   if (node->state_.timestamp <= last_interpreted_time_) {
     // Time wouldn't seem monotonically increasing w/ this new event, so
     // discard it.
-    free_list_.PushBack(node);
-    return;
+    free_list_.push_back(node);
+  } else {
+    queue_.insert(--queue_.end(), node);
   }
-
-  queue_.InsertBefore(new_node, node);
 }
 
 void LookaheadFilterInterpreter::HandleTimerImpl(stime_t now,
@@ -440,12 +447,16 @@ void LookaheadFilterInterpreter::HandleTimerImpl(stime_t now,
       last_interpreted_time_ = now;
       next_->HandleTimer(now, &next_timeout);
     } else {
-      if (queue_.Empty())
+      if (queue_.empty())
         break;
       // Get next uncompleted and overdue hwstate
-      QState* node = queue_.Head();
-      while (node != queue_.Tail() && node->completed_)
-        node = node->next_;
+      auto node = queue_.back();
+      for (auto state : queue_) {
+        if (!state->completed_) {
+          node = state;
+          break;
+        }
+      }
       if (node->completed_ || node->due_ > now)
         break;
       next_timeout = NO_DEADLINE;
@@ -471,8 +482,10 @@ void LookaheadFilterInterpreter::HandleTimerImpl(stime_t now,
       next_->SyncInterpret(&hs_copy, &next_timeout);
 
       // Clear previously completed nodes, but keep at least two nodes.
-      while (queue_.size() > 2 && queue_.Head()->completed_)
-        free_list_.PushBack(queue_.PopFront());
+      while (queue_.size() > 2 && queue_.front()->completed_) {
+        free_list_.push_back(queue_.front());
+        queue_.pop_front();
+      }
 
       // Mark current node completed. This should be the only completed
       // node in the queue.
@@ -489,7 +502,7 @@ void LookaheadFilterInterpreter::HandleTimerImpl(stime_t now,
 }
 
 void LookaheadFilterInterpreter::ConsumeGesture(const Gesture& gesture) {
-  QState* node = queue_.Head();
+  QState* node = queue_.front();
 
   float distance_sq = 0.0;
   // Slow movements should potentially be suppressed
@@ -516,10 +529,11 @@ void LookaheadFilterInterpreter::ConsumeGesture(const Gesture& gesture) {
     return;
   }
   // Speed is slow. Suppress if fingers have changed.
-  for (QState* iter = node->next_; iter != queue_.End(); iter = iter->next_)
-    if (!node->state_.SameFingersAs(iter->state_) ||
-        (node->state_.buttons_down != iter->state_.buttons_down))
+  for (auto iter = ++queue_.begin(); iter != queue_.end(); ++iter) {
+    if (!node->state_.SameFingersAs((*iter)->state_) ||
+        (node->state_.buttons_down != (*iter)->state_.buttons_down))
       return; // suppress
+  }
 
   ProduceGesture(gesture);
 }
@@ -532,11 +546,10 @@ void LookaheadFilterInterpreter::UpdateInterpreterDue(
   // timeout, so we use -DBL_MAX as the invalid value.
   stime_t next_hwstate_timeout = -DBL_MAX;
   // Scan queue_ to find when next hwstate is due.
-  for (QState* node = queue_.Begin(); node != queue_.End();
-       node = node->next_) {
-    if (node->completed_)
+  for (auto elem : queue_) {
+    if (elem->completed_)
       continue;
-    next_hwstate_timeout = node->due_ - now;
+    next_hwstate_timeout = elem->due_ - now;
     break;
   }
 
@@ -557,12 +570,11 @@ void LookaheadFilterInterpreter::Initialize(
     MetricsProperties* mprops,
     GestureConsumer* consumer) {
   FilterInterpreter::Initialize(hwprops, NULL, mprops, consumer);
-  const size_t kMaxQNodes = 16;
-  queue_.DeleteAll();
-  free_list_.DeleteAll();
+  queue_.clear();
+  free_list_.clear();
   for (size_t i = 0; i < kMaxQNodes; ++i) {
     QState* node = new QState(hwprops_->max_finger_cnt);
-    free_list_.PushBack(node);
+    free_list_.push_back(node);
   }
 }
 
@@ -603,4 +615,25 @@ void LookaheadFilterInterpreter::QState::set_state(
   state_.msc_timestamp = new_state.msc_timestamp;
 }
 
+LookaheadFilterInterpreter::QState*
+LookaheadFilterInterpreter::QStateList::at(int offset) {
+  // Traverse to the appropriate offset
+  if (offset < 0) {
+    // negative offset is from end to begin
+    auto count = size();
+    for (auto iter = --end(); count > 0; --count, --iter) {
+      if (++offset == 0)
+        return *iter;
+    }
+  } else {
+    // positive offset is from begin to end
+    for (auto elem : *this) {
+      if (offset-- == 0)
+        return elem;
+    }
+  }
+  // invalid offset returns NULL
+  return nullptr;
+}
+
 }  // namespace gestures
diff --git a/src/lookahead_filter_interpreter_unittest.cc b/src/lookahead_filter_interpreter_unittest.cc
index 788d785..1c84eb4 100644
--- a/src/lookahead_filter_interpreter_unittest.cc
+++ b/src/lookahead_filter_interpreter_unittest.cc
@@ -788,42 +788,42 @@ TEST(LookaheadFilterInterpreterTest, QuickMoveTest) {
   wrapper.Reset(interpreter.get());
 
   stime_t timeout = NO_DEADLINE;
-  List<LookaheadFilterInterpreter::QState>* queue = &interpreter->queue_;
+  const auto& queue = interpreter->queue_;
 
   // Pushing the first event
   wrapper.SyncInterpret(&hs[0], &timeout);
-  EXPECT_EQ(queue->size(), 1);
-  EXPECT_EQ(queue->Tail()->fs_[0].tracking_id, 1);
+  EXPECT_EQ(queue.size(), 1);
+  EXPECT_EQ(queue.back()->fs_[0].tracking_id, 1);
 
   // Expecting Drumroll detected and ID reassigned 1 -> 2.
   wrapper.SyncInterpret(&hs[1], &timeout);
-  EXPECT_EQ(queue->size(), 2);
-  EXPECT_EQ(queue->Tail()->fs_[0].tracking_id, 2);
+  EXPECT_EQ(queue.size(), 2);
+  EXPECT_EQ(queue.back()->fs_[0].tracking_id, 2);
 
   // Expecting Drumroll detected and ID reassigned 1 -> 3.
   wrapper.SyncInterpret(&hs[2], &timeout);
-  EXPECT_EQ(queue->size(), 3);
-  EXPECT_EQ(queue->Tail()->fs_[0].tracking_id, 3);
+  EXPECT_EQ(queue.size(), 3);
+  EXPECT_EQ(queue.back()->fs_[0].tracking_id, 3);
 
   // Removing the touch.
   wrapper.SyncInterpret(&hs[3], &timeout);
-  EXPECT_EQ(queue->size(), 4);
+  EXPECT_EQ(queue.size(), 4);
 
   // New event comes, old events removed from the queue.
   // New finger tracking ID assigned 2 - > 4.
   wrapper.SyncInterpret(&hs[4], &timeout);
-  EXPECT_EQ(queue->size(), 2);
-  EXPECT_EQ(queue->Tail()->fs_[0].tracking_id, 4);
+  EXPECT_EQ(queue.size(), 2);
+  EXPECT_EQ(queue.back()->fs_[0].tracking_id, 4);
 
   // Expecting Drumroll detected and ID reassigned 2 -> 5.
   wrapper.SyncInterpret(&hs[5], &timeout);
-  EXPECT_EQ(queue->Tail()->fs_[0].tracking_id, 5);
+  EXPECT_EQ(queue.back()->fs_[0].tracking_id, 5);
 
   // Expecting Quick movement detected and ID correction 5 -> 4.
   wrapper.SyncInterpret(&hs[6], &timeout);
-  EXPECT_EQ(queue->Tail()->fs_[0].tracking_id, 4);
-  EXPECT_EQ(queue->Tail()->prev_->fs_[0].tracking_id, 4);
-  EXPECT_EQ(queue->Tail()->prev_->prev_->fs_[0].tracking_id, 4);
+  EXPECT_EQ(interpreter->queue_.at(-1)->fs_[0].tracking_id, 4);
+  EXPECT_EQ(interpreter->queue_.at(-2)->fs_[0].tracking_id, 4);
+  EXPECT_EQ(interpreter->queue_.at(-3)->fs_[0].tracking_id, 4);
 }
 
 struct QuickSwipeTestInputs {
@@ -1263,16 +1263,79 @@ TEST(LookaheadFilterInterpreterTest, SemiMtNoTrackingIdAssignmentTest) {
   wrapper.Reset(interpreter.get());
 
   stime_t timeout = NO_DEADLINE;
-  List<LookaheadFilterInterpreter::QState>* queue = &interpreter->queue_;
+  const auto& queue = interpreter->queue_;
 
   wrapper.SyncInterpret(&hs[0], &timeout);
-  EXPECT_EQ(queue->Tail()->fs_[0].tracking_id, 20);
+  EXPECT_EQ(queue.back()->fs_[0].tracking_id, 20);
 
   // Test if the fingers in queue have the same tracking ids from input.
   for (size_t i = 1; i < arraysize(hs); i++) {
     wrapper.SyncInterpret(&hs[i], &timeout);
-    EXPECT_EQ(queue->Tail()->fs_[0].tracking_id, 20);  // the same input id
-    EXPECT_EQ(queue->Tail()->fs_[1].tracking_id, 21);
+    EXPECT_EQ(queue.back()->fs_[0].tracking_id, 20);  // the same input id
+    EXPECT_EQ(queue.back()->fs_[1].tracking_id, 21);
   }
 }
+
+TEST(LookaheadFilterInterpreterTest, QStateListTest) {
+  LookaheadFilterInterpreterTestInterpreter* base_interpreter = NULL;
+  std::unique_ptr<LookaheadFilterInterpreter> interpreter;
+
+  HardwareProperties hwprops = {
+    0, 0, 100, 100,  // left, top, right, bottom
+    1,  // x res (pixels/mm)
+    1,  // y res (pixels/mm)
+    25, 25,  // scrn DPI X, Y
+    -1,  // orientation minimum
+    2,   // orientation maximum
+    2, 5,  // max fingers, max_touch
+    1, 1, 0,  // t5r2, semi, button pad
+    0, 0,  // has wheel, vertical wheel is high resolution
+    0,  // haptic pad
+  };
+  TestInterpreterWrapper wrapper(interpreter.get(), &hwprops);
+
+  base_interpreter = new LookaheadFilterInterpreterTestInterpreter;
+  interpreter.reset(new LookaheadFilterInterpreter(
+      NULL, base_interpreter, NULL));
+  wrapper.Reset(interpreter.get());
+
+  auto& queue = interpreter->queue_;
+  auto& free_list = interpreter->free_list_;
+
+  // Release all of the QStates
+  while (!queue.empty()) {
+    free_list.push_back(queue.front());
+    queue.pop_front();
+  }
+  EXPECT_EQ(queue.size(), 0);
+  EXPECT_EQ(free_list.size(), 16);
+
+  EXPECT_EQ(queue.at(-1), nullptr);
+  EXPECT_EQ(queue.at(queue.size()), nullptr);
+
+  // fill up the QStates
+  while (!free_list.empty()) {
+    queue.push_front(free_list.back());
+    free_list.pop_back();
+  }
+  EXPECT_EQ(queue.size(), 16);
+  EXPECT_EQ(free_list.size(), 0);
+
+  EXPECT_NE(queue.at(-1), nullptr);
+  EXPECT_EQ(queue.at(-1), queue.at(queue.size() - 1));
+
+  EXPECT_EQ(queue.at(queue.size()), nullptr);
+
+  for (int i = 0; i < 16; ++i) {
+    for (int j = 0; j < 16; ++j) {
+      if (i == j) {
+        EXPECT_EQ(queue.at(i), queue.at(j));
+      } else {
+        EXPECT_NE(queue.at(i), queue.at(j));
+      }
+    }
+  }
+
+  LookaheadFilterInterpreter::QState qs;
+}
 }  // namespace gestures
diff --git a/src/metrics_filter_interpreter.cc b/src/metrics_filter_interpreter.cc
index e608f23..de6ca33 100644
--- a/src/metrics_filter_interpreter.cc
+++ b/src/metrics_filter_interpreter.cc
@@ -142,7 +142,7 @@ void MetricsFilterInterpreter::UpdateFingerState(
   RemoveMissingIdsFromMap(&histories_, hwstate, &removed);
   for (FingerHistoryMap::const_iterator it =
        removed.begin(); it != removed.end(); ++it) {
-    it->second->DeleteAll();
+    it->second->clear();
     history_mm_.Free(it->second);
 }
 
@@ -171,14 +171,15 @@ void MetricsFilterInterpreter::UpdateFingerState(
 
 bool MetricsFilterInterpreter::DetectNoisyGround(
     const FingerHistory* history) {
-  MState* current = history->Tail();
+  auto iter = history->end();
+  MState* current = *(--iter);
   size_t n_samples = history->size();
   // Noise pattern takes 3 samples
   if (n_samples < 3)
     return false;
 
-  MState* past_1 = current->prev_;
-  MState* past_2 = past_1->prev_;
+  MState* past_1 = *(--iter);
+  MState* past_2 = *(--iter);
   // Noise pattern needs to happen in a short period of time
   if(current->timestamp - past_2->timestamp >
       noisy_ground_time_threshold_.val_) {
diff --git a/src/mouse_interpreter.cc b/src/mouse_interpreter.cc
index b26de8f..f3055b3 100644
--- a/src/mouse_interpreter.cc
+++ b/src/mouse_interpreter.cc
@@ -29,8 +29,7 @@ MouseInterpreter::MouseInterpreter(PropRegistry* prop_reg, Tracer* tracer)
           scroll_accel_curve_, sizeof(scroll_accel_curve_) / sizeof(double)),
       scroll_max_allowed_input_speed_(prop_reg,
                                       "Mouse Scroll Max Input Speed",
-                                      177.0,
-                                      this),
+                                      177.0),
       force_scroll_wheel_emulation_(prop_reg,
                                      "Force Scroll Wheel Emulation",
                                      false),
@@ -53,6 +52,7 @@ MouseInterpreter::MouseInterpreter(PropRegistry* prop_reg, Tracer* tracer)
   scroll_accel_curve_[2] = 2.5737e-02;
   scroll_accel_curve_[3] = 8.0428e-05;
   scroll_accel_curve_[4] = -9.1149e-07;
+  scroll_max_allowed_input_speed_.SetDelegate(this);
 }
 
 void MouseInterpreter::SyncInterpretImpl(HardwareState* hwstate,
diff --git a/src/prop_registry.cc b/src/prop_registry.cc
index 58e3a1a..2d9d454 100644
--- a/src/prop_registry.cc
+++ b/src/prop_registry.cc
@@ -70,18 +70,6 @@ void Property::DestroyProp() {
   gprop_ = NULL;
 }
 
-void Property::SetDelegate(PropertyDelegate* delegate) {
-  bool delegate_was_late_set = !delegate_ && delegate;
-  delegate_ = delegate;
-  // In the normal path of creation of a property with a parent, the
-  // delegate is set late and the CreatePropImpl will not call the
-  // WasWritten method.  So catch the transition from NULL to not
-  // NULL in this condition and make sure to call the initial
-  // WasWritten to mimick the original code.
-  if (delegate_was_late_set && parent_ && parent_->PropProvider())
-    HandleGesturesPropWritten();
-}
-
 void BoolProperty::CreatePropImpl() {
   GesturesPropBool orig_val = val_;
   gprop_ = parent_->PropProvider()->create_bool_fn(
diff --git a/src/prop_registry_unittest.cc b/src/prop_registry_unittest.cc
index 23ba9d8..503a552 100644
--- a/src/prop_registry_unittest.cc
+++ b/src/prop_registry_unittest.cc
@@ -48,7 +48,8 @@ TEST(PropRegistryTest, SimpleTest) {
   PropRegistryTestDelegate delegate;
 
   int expected_call_cnt = 0;
-  BoolProperty bp1(&reg, "hi", false, &delegate);
+  BoolProperty bp1(&reg, "hi", false);
+  bp1.SetDelegate(&delegate);
   EXPECT_TRUE(strstr(ValueForProperty(bp1).c_str(), "false"));
   bp1.HandleGesturesPropWritten();
   EXPECT_EQ(++expected_call_cnt, delegate.call_cnt_);
@@ -58,7 +59,8 @@ TEST(PropRegistryTest, SimpleTest) {
   bp2.HandleGesturesPropWritten();
   EXPECT_EQ(expected_call_cnt, delegate.call_cnt_);
 
-  DoubleProperty dp1(&reg, "hi", 2721.0, &delegate);
+  DoubleProperty dp1(&reg, "hi", 2721.0);
+  dp1.SetDelegate(&delegate);
   EXPECT_TRUE(strstr(ValueForProperty(dp1).c_str(), "2721"));
   dp1.HandleGesturesPropWritten();
   EXPECT_EQ(++expected_call_cnt, delegate.call_cnt_);
@@ -68,7 +70,8 @@ TEST(PropRegistryTest, SimpleTest) {
   dp2.HandleGesturesPropWritten();
   EXPECT_EQ(expected_call_cnt, delegate.call_cnt_);
 
-  IntProperty ip1(&reg, "hi", 567, &delegate);
+  IntProperty ip1(&reg, "hi", 567);
+  ip1.SetDelegate(&delegate);
   EXPECT_TRUE(strstr(ValueForProperty(ip1).c_str(), "567"));
   ip1.HandleGesturesPropWritten();
   EXPECT_EQ(++expected_call_cnt, delegate.call_cnt_);
@@ -78,7 +81,8 @@ TEST(PropRegistryTest, SimpleTest) {
   ip2.HandleGesturesPropWritten();
   EXPECT_EQ(expected_call_cnt, delegate.call_cnt_);
 
-  StringProperty stp1(&reg, "hi", "foo", &delegate);
+  StringProperty stp1(&reg, "hi", "foo");
+  stp1.SetDelegate(&delegate);
   EXPECT_TRUE(strstr(ValueForProperty(stp1).c_str(), "foo"));
   stp1.HandleGesturesPropWritten();
   EXPECT_EQ(++expected_call_cnt, delegate.call_cnt_);
@@ -194,29 +198,31 @@ TEST(PropRegistryTest, SetAtCreateShouldNotifyTest) {
 
   PropRegistry reg;
   PropRegistryTestDelegate delegate;
-  BoolProperty my_bool(&reg, "MyBool", 0, &delegate);
-  DoubleProperty my_double(&reg, "MyDouble", 0.0, &delegate);
-  IntProperty my_int(&reg, "MyInt", 0, &delegate);
-  IntProperty my_int_no_change(&reg, "MyIntNoChange", 1, &delegate);
-  StringProperty my_string(&reg, "MyString", "mine", &delegate);
+  BoolProperty my_bool(&reg, "MyBool", 0);
+  my_bool.SetDelegate(&delegate);
+  DoubleProperty my_double(&reg, "MyDouble", 0.0);
+  my_double.SetDelegate(&delegate);
+  IntProperty my_int(&reg, "MyInt", 0);
+  my_int.SetDelegate(&delegate);
+  IntProperty my_int_no_change(&reg, "MyIntNoChange", 1);
+  my_int_no_change.SetDelegate(&delegate);
+  StringProperty my_string(&reg, "MyString", "mine");
+  my_string.SetDelegate(&delegate);
 
   EXPECT_EQ(0, delegate.call_cnt_);
   reg.SetPropProvider(&mock_gestures_props_provider, NULL);
   EXPECT_EQ(4, delegate.call_cnt_);
-
-  BoolProperty my_bool2(&reg, "MyBool2", 1);
-  EXPECT_EQ(4, delegate.call_cnt_);
-  my_bool2.SetDelegate(&delegate);
-  EXPECT_EQ(5, delegate.call_cnt_);
 }
 
 TEST(PropRegistryTest, DoublePromoteIntTest) {
   PropRegistry reg;
   PropRegistryTestDelegate delegate;
 
-  DoubleProperty my_double(&reg, "MyDouble", 1234.5, &delegate);
+  DoubleProperty my_double(&reg, "MyDouble", 1234.5);
+  my_double.SetDelegate(&delegate);
   EXPECT_TRUE(strstr(ValueForProperty(my_double).c_str(), "1234.5"));
-  IntProperty my_int(&reg, "MyInt", 321, &delegate);
+  IntProperty my_int(&reg, "MyInt", 321);
+  my_int.SetDelegate(&delegate);
   Json::Value my_int_val = my_int.NewValue();
   EXPECT_TRUE(my_double.SetValue(my_int_val));
   EXPECT_TRUE(strstr(ValueForProperty(my_double).c_str(), "321"));
@@ -229,15 +235,18 @@ TEST(PropRegistryTest, BoolArrayTest) {
 
   GesturesPropBool vals[] = { false, true };
   BoolArrayProperty my_bool_array_w_delegate(
-    &reg, "MyBoolArray", vals, 2, &delegate);
+    &reg, "MyBoolArray", vals, 2);
+  my_bool_array_w_delegate.SetDelegate(&delegate);
   EXPECT_EQ(0, delegate.call_cnt_);
   my_bool_array_w_delegate.HandleGesturesPropWritten();
   EXPECT_EQ(1, delegate.call_cnt_);
   delegate.BoolArrayWasWritten(&my_bool_array_w_delegate);
   EXPECT_EQ(2, delegate.call_cnt_);
 
-  IntProperty ip1(&reg, "hi", 567, &delegate);
-  StringProperty stp1(&reg, "hi", "foo", &delegate);
+  IntProperty ip1(&reg, "hi", 567);
+  ip1.SetDelegate(&delegate);
+  StringProperty stp1(&reg, "hi", "foo");
+  stp1.SetDelegate(&delegate);
   Json::Value my_bool_array_val = my_bool_array_w_delegate.NewValue();
   Json::Value my_int_val = ip1.NewValue();
   Json::Value my_str_val = stp1.NewValue();
@@ -261,15 +270,18 @@ TEST(PropRegistryTest, DoubleArrayTest) {
 
   double vals[] = { 0.0, 1.0 };
   DoubleArrayProperty my_double_array_w_delegate(
-    &reg, "MyDoubleArray", vals, 2, &delegate);
+    &reg, "MyDoubleArray", vals, 2);
+  my_double_array_w_delegate.SetDelegate(&delegate);
   EXPECT_EQ(0, delegate.call_cnt_);
   my_double_array_w_delegate.HandleGesturesPropWritten();
   EXPECT_EQ(1, delegate.call_cnt_);
   delegate.DoubleArrayWasWritten(&my_double_array_w_delegate);
   EXPECT_EQ(2, delegate.call_cnt_);
 
-  IntProperty ip1(&reg, "hi", 567, &delegate);
-  StringProperty stp1(&reg, "hi", "foo", &delegate);
+  IntProperty ip1(&reg, "hi", 567);
+  ip1.SetDelegate(&delegate);
+  StringProperty stp1(&reg, "hi", "foo");
+  stp1.SetDelegate(&delegate);
   Json::Value my_double_array_val = my_double_array_w_delegate.NewValue();
   Json::Value my_int_val = ip1.NewValue();
   Json::Value my_str_val = stp1.NewValue();
@@ -293,15 +305,18 @@ TEST(PropRegistryTest, IntArrayTest) {
 
   int vals[] = { 0, 1 };
   IntArrayProperty my_int_array_w_delegate(
-    &reg, "MyIntArray", vals, 2, &delegate);
+    &reg, "MyIntArray", vals, 2);
+  my_int_array_w_delegate.SetDelegate(&delegate);
   EXPECT_EQ(0, delegate.call_cnt_);
   my_int_array_w_delegate.HandleGesturesPropWritten();
   EXPECT_EQ(1, delegate.call_cnt_);
   delegate.IntArrayWasWritten(&my_int_array_w_delegate);
   EXPECT_EQ(2, delegate.call_cnt_);
 
-  IntProperty ip1(&reg, "hi", 567, &delegate);
-  StringProperty stp1(&reg, "hi", "foo", &delegate);
+  IntProperty ip1(&reg, "hi", 567);
+  ip1.SetDelegate(&delegate);
+  StringProperty stp1(&reg, "hi", "foo");
+  stp1.SetDelegate(&delegate);
   Json::Value my_int_array_val = my_int_array_w_delegate.NewValue();
   Json::Value my_int_val = ip1.NewValue();
   Json::Value my_str_val = stp1.NewValue();
diff --git a/src/scaling_filter_interpreter.cc b/src/scaling_filter_interpreter.cc
index 1094455..2d2aad9 100644
--- a/src/scaling_filter_interpreter.cc
+++ b/src/scaling_filter_interpreter.cc
@@ -318,8 +318,13 @@ void ScalingFilterInterpreter::Initialize(const HardwareProperties* hwprops,
                                           Metrics* metrics,
                                           MetricsProperties* mprops,
                                           GestureConsumer* consumer) {
-  tp_x_scale_ = 1.0 / hwprops->res_x;
-  tp_y_scale_ = 1.0 / hwprops->res_y;
+  // If the touchpad doesn't specify its resolution in one or both axes, use a
+  // reasonable default instead.
+  float res_x = hwprops->res_x != 0 ? hwprops->res_x : 32;
+  float res_y = hwprops->res_y != 0 ? hwprops->res_y : 32;
+
+  tp_x_scale_ = 1.0 / res_x;
+  tp_y_scale_ = 1.0 / res_y;
   tp_x_translate_ = -1.0 * (hwprops->left * tp_x_scale_);
   tp_y_translate_ = -1.0 * (hwprops->top * tp_y_scale_);
 
diff --git a/src/scaling_filter_interpreter_unittest.cc b/src/scaling_filter_interpreter_unittest.cc
index d701c7f..93f8e79 100644
--- a/src/scaling_filter_interpreter_unittest.cc
+++ b/src/scaling_filter_interpreter_unittest.cc
@@ -68,7 +68,7 @@ class ScalingFilterInterpreterTestInterpreter : public Interpreter {
       EXPECT_FLOAT_EQ(expected_pressures_.front(),
                       hwstate->fingers[0].pressure);
       expected_pressures_.pop_front();
-    } else {
+    } else if (!expected_finger_cnt_.empty() && !expected_touch_cnt_.empty()) {
       // Test if the low pressure event is dropped
       EXPECT_EQ(expected_finger_cnt_.front(), hwstate->finger_cnt);
       expected_finger_cnt_.pop_front();
@@ -272,6 +272,47 @@ TEST(ScalingFilterInterpreterTest, SimpleTest) {
   out = wrapper.SyncInterpret(&hs2[2], NULL);
 }
 
+TEST(ScalingFilterInterpreterTest, ResolutionFallback) {
+  ScalingFilterInterpreterTestInterpreter* base_interpreter =
+      new ScalingFilterInterpreterTestInterpreter;
+  ScalingFilterInterpreter interpreter(NULL, base_interpreter, NULL,
+                                       GESTURES_DEVCLASS_TOUCHPAD);
+  HardwareProperties initial_hwprops = {
+    0, 0, 2000, 1000,  // left, top, right, bottom
+    0, 0,  // X/Y resolutions (pixels/mm)
+    0, 0,  // screen DPI X, Y (deprecated)
+    -1,  // orientation minimum
+    2,   // orientation maximum
+    2, 5,  // max fingers, max_touch
+    0, 0, 0,  // t5r2, semi, button pad
+    0, 0,  // has wheel, vertical wheel is high resolution
+    0,  // haptic pad
+  };
+  HardwareProperties expected_hwprops = {
+    0, 0, 2000 / 32.0, 1000 / 32.0,  // left, top, right, bottom
+    1, 1,  // X/Y resolutions (pixels/mm)
+    25.4, 25.4, // x DPI, y DPI
+    -M_PI_4,  // orientation minimum (1 tick above X-axis)
+    M_PI_2,   // orientation maximum
+    2, 5, 0, 0, 0,  // max_fingers, max_touch, t5r2, semi_mt, is button pad
+    0, 0,  // has wheel, vertical wheel is high resolution
+    0,  // is haptic pad
+  };
+  base_interpreter->expected_hwprops_ = expected_hwprops;
+
+  TestInterpreterWrapper wrapper(&interpreter, &initial_hwprops);
+  EXPECT_TRUE(base_interpreter->initialize_called_);
+
+  FingerState fs = { 1, 0, 0, 0, 1, 0, 1000, 500, 1, 0 };
+  HardwareState hs = make_hwstate(10000, 0, 1, 1, &fs);
+
+  base_interpreter->expected_coordinates_.push_back(
+      std::vector<pair<float, float>>(1, make_pair(
+          static_cast<float>(1000 / 32.0), static_cast<float>(500 / 32.0))));
+
+  wrapper.SyncInterpret(&hs, NULL);
+}
+
 static void RunTouchMajorAndMinorTest(
     ScalingFilterInterpreterTestInterpreter* base_interpreter,
     ScalingFilterInterpreter* interpreter,
diff --git a/src/trend_classifying_filter_interpreter.cc b/src/trend_classifying_filter_interpreter.cc
index 45699a9..d6ddd21 100644
--- a/src/trend_classifying_filter_interpreter.cc
+++ b/src/trend_classifying_filter_interpreter.cc
@@ -78,7 +78,7 @@ void TrendClassifyingFilterInterpreter::AddNewStateToBuffer(
     history->DeleteFront();
 
   // Push the new finger state to the back of buffer
-  KState* previous_end = history->Tail();
+  KState* previous_end = history->back();
   KState* current = history->PushNewEltBack();
   if (!current) {
     Err("KState buffer out of space");
@@ -94,10 +94,10 @@ void TrendClassifyingFilterInterpreter::AddNewStateToBuffer(
   // variance along the way. Complexity is O(|buffer|) per finger.
   int tie_n2[KState::n_axes_] = { 0, 0, 0, 0, 0, 0 };
   int tie_n3[KState::n_axes_] = { 0, 0, 0, 0, 0, 0 };
-  for (KState* it = history->Begin(); it != history->Tail(); it = it->next_)
+  for (auto it = history->begin(); it != history->end(); ++it)
     for (size_t i = 0; i < KState::n_axes_; i++)
-      if(it != history->Begin() || !KState::IsDelta(i)) {
-        UpdateKTValuePair(&it->axes_[i], &current->axes_[i],
+      if (it != history->begin() || !KState::IsDelta(i)) {
+        UpdateKTValuePair(&(*it)->axes_[i], &current->axes_[i],
             &tie_n2[i], &tie_n3[i]);
       }
   size_t n_samples = history->size();
@@ -136,7 +136,7 @@ void TrendClassifyingFilterInterpreter::UpdateFingerState(
   RemoveMissingIdsFromMap(&histories_, hwstate, &removed);
   for (FingerHistoryMap::const_iterator it =
        removed.begin(); it != removed.end(); ++it) {
-    it->second->DeleteAll();
+    it->second->clear();
     history_mm_.Free(it->second);
   }
 
@@ -159,7 +159,7 @@ void TrendClassifyingFilterInterpreter::UpdateFingerState(
 
     // Check if the score demonstrates statistical significance
     AddNewStateToBuffer(hp, fs[i]);
-    KState* current = hp->Tail();
+    KState* current = hp->back();
     size_t n_samples = hp->size();
     for (size_t idx = 0; idx < KState::n_axes_; idx++)
       if (second_order_enable_.val_ || !KState::IsDelta(idx)) {
diff --git a/tools/local_coverage_rate.sh b/tools/local_coverage_rate.sh
index 710d91c..d1f9fff 100755
--- a/tools/local_coverage_rate.sh
+++ b/tools/local_coverage_rate.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+# Copyright 2011 The ChromiumOS Authors
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
diff --git a/tools/regression_test.sh b/tools/regression_test.sh
index db7535b..f97118a 100755
--- a/tools/regression_test.sh
+++ b/tools/regression_test.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+# Copyright 2012 The ChromiumOS Authors
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
diff --git a/tools/replay_log b/tools/replay_log
index bfdca70..76ddbbd 100755
--- a/tools/replay_log
+++ b/tools/replay_log
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+# Copyright 2012 The ChromiumOS Authors
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
diff --git a/tools/tplog.py b/tools/tplog.py
index b2a685f..3ede9b7 100755
--- a/tools/tplog.py
+++ b/tools/tplog.py
@@ -1,6 +1,6 @@
 #!/usr/bin/python
 #
-# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+# Copyright 2012 The ChromiumOS Authors
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.