1 files changed, 22 insertions, 34 deletions

diff --git a/base/threading/platform_thread.h b/base/threading/platform_thread.h
index 3468f45f91..e2b09bcb5b 100644
--- a/base/threading/platform_thread.h
+++ b/base/threading/platform_thread.h
@@ -9,8 +9,10 @@
 #ifndef BASE_THREADING_PLATFORM_THREAD_H_
 #define BASE_THREADING_PLATFORM_THREAD_H_
 
+#include <stddef.h>
+
 #include "base/base_export.h"
-#include "base/basictypes.h"
+#include "base/macros.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 
@@ -73,25 +75,9 @@ class PlatformThreadHandle {
   typedef pthread_t Handle;
 #endif
 
-  PlatformThreadHandle()
-      : handle_(0),
-        id_(0) {
-  }
-
-  explicit PlatformThreadHandle(Handle handle)
-      : handle_(handle),
-        id_(0) {
-  }
-
-  PlatformThreadHandle(Handle handle,
-                       PlatformThreadId id)
-      : handle_(handle),
-        id_(id) {
-  }
+  PlatformThreadHandle() : handle_(0) {}
 
-  PlatformThreadId id() const {
-    return id_;
-  }
+  explicit PlatformThreadHandle(Handle handle) : handle_(handle) {}
 
   bool is_equal(const PlatformThreadHandle& other) const {
     return handle_ == other.handle_;
@@ -107,13 +93,12 @@ class PlatformThreadHandle {
 
  private:
   Handle handle_;
-  PlatformThreadId id_;
 };
 
 const PlatformThreadId kInvalidThreadId(0);
 
-// Valid values for SetThreadPriority(), listed in increasing order of
-// importance.
+// Valid values for priority of Thread::Options and SimpleThread::Options, and
+// SetCurrentThreadPriority(), listed in increasing order of importance.
 enum class ThreadPriority {
   // Suitable for threads that shouldn't disrupt high priority work.
   BACKGROUND,
@@ -172,12 +157,15 @@ class BASE_EXPORT PlatformThread {
   // NOTE: When you are done with the thread handle, you must call Join to
   // release system resources associated with the thread.  You must ensure that
   // the Delegate object outlives the thread.
-  static bool Create(size_t stack_size, Delegate* delegate,
-                     PlatformThreadHandle* thread_handle);
+  static bool Create(size_t stack_size,
+                     Delegate* delegate,
+                     PlatformThreadHandle* thread_handle) {
+    return CreateWithPriority(stack_size, delegate, thread_handle,
+                              ThreadPriority::NORMAL);
+  }
 
   // CreateWithPriority() does the same thing as Create() except the priority of
-  // the thread is set based on |priority|.  Can be used in place of Create()
-  // followed by SetThreadPriority().
+  // the thread is set based on |priority|.
   static bool CreateWithPriority(size_t stack_size, Delegate* delegate,
                                  PlatformThreadHandle* thread_handle,
                                  ThreadPriority priority);
@@ -192,15 +180,15 @@ class BASE_EXPORT PlatformThread {
   // |thread_handle|.
   static void Join(PlatformThreadHandle thread_handle);
 
-  // Toggles the target thread's priority at runtime.  Prefer
-  // CreateWithPriority() to set the thread's initial priority.
-  // NOTE: The call may fail if the caller thread is not the same as the
-  // target thread on POSIX.  For example, seccomp-bpf blocks it by default
-  // in the sandbox.
-  static void SetThreadPriority(PlatformThreadHandle handle,
-                                ThreadPriority priority);
+  // Toggles the current thread's priority at runtime. A thread may not be able
+  // to raise its priority back up after lowering it if the process does not
+  // have a proper permission, e.g. CAP_SYS_NICE on Linux.
+  // Since changing other threads' priority is not permitted in favor of
+  // security, this interface is restricted to change only the current thread
+  // priority (https://crbug.com/399473).
+  static void SetCurrentThreadPriority(ThreadPriority priority);
 
-  static ThreadPriority GetThreadPriority(PlatformThreadHandle handle);
+  static ThreadPriority GetCurrentThreadPriority();
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PlatformThread);