Revert "libmojo: Uprev the library to r456626 from Chromium"

This reverts commit 8ac9103e05b66812c25348943383f9365d1ce3e0.

Reason for revert: Broke the mac_sdk
Exempt-From-Owner-Approval: Fixing mac_sdk

Change-Id: I0b74d1abaa66933a93fd6f82ff018e8948c1204e

1 files changed, 28 insertions, 9 deletions

diff --git a/mojo/public/cpp/bindings/lib/message_buffer.cc b/mojo/public/cpp/bindings/lib/message_buffer.cc
index cc12ef6..af79cfd 100644
--- a/mojo/public/cpp/bindings/lib/message_buffer.cc
+++ b/mojo/public/cpp/bindings/lib/message_buffer.cc
@@ -13,35 +13,54 @@ namespace internal {
 
 MessageBuffer::MessageBuffer(size_t capacity, bool zero_initialized) {
   DCHECK_LE(capacity, std::numeric_limits<uint32_t>::max());
+  data_num_bytes_ = static_cast<uint32_t>(capacity);
 
   MojoResult rv = AllocMessage(capacity, nullptr, 0,
                                MOJO_ALLOC_MESSAGE_FLAG_NONE, &message_);
   CHECK_EQ(rv, MOJO_RESULT_OK);
 
-  void* buffer = nullptr;
-  if (capacity != 0) {
-    rv = GetMessageBuffer(message_.get(), &buffer);
+  if (capacity == 0) {
+    buffer_ = nullptr;
+  } else {
+    rv = GetMessageBuffer(message_.get(), &buffer_);
     CHECK_EQ(rv, MOJO_RESULT_OK);
 
     if (zero_initialized)
-      memset(buffer, 0, capacity);
+      memset(buffer_, 0, capacity);
   }
-  Initialize(buffer, capacity);
 }
 
 MessageBuffer::MessageBuffer(ScopedMessageHandle message, uint32_t num_bytes) {
   message_ = std::move(message);
+  data_num_bytes_ = num_bytes;
 
-  void* buffer = nullptr;
-  if (num_bytes != 0) {
-    MojoResult rv = GetMessageBuffer(message_.get(), &buffer);
+  if (num_bytes == 0) {
+    buffer_ = nullptr;
+  } else {
+    MojoResult rv = GetMessageBuffer(message_.get(), &buffer_);
     CHECK_EQ(rv, MOJO_RESULT_OK);
   }
-  Initialize(buffer, num_bytes);
 }
 
 MessageBuffer::~MessageBuffer() {}
 
+void* MessageBuffer::Allocate(size_t delta) {
+  delta = internal::Align(delta);
+
+  DCHECK_LE(delta, static_cast<size_t>(data_num_bytes_));
+  DCHECK_GT(bytes_claimed_ + static_cast<uint32_t>(delta), bytes_claimed_);
+
+  uint32_t new_bytes_claimed = bytes_claimed_ + static_cast<uint32_t>(delta);
+  if (new_bytes_claimed > data_num_bytes_) {
+    NOTREACHED();
+    return nullptr;
+  }
+
+  char* start = static_cast<char*>(buffer_) + bytes_claimed_;
+  bytes_claimed_ = new_bytes_claimed;
+  return static_cast<void*>(start);
+}
+
 void MessageBuffer::NotifyBadMessage(const std::string& error) {
   DCHECK(message_.is_valid());
   MojoResult result = mojo::NotifyBadMessage(message_.get(), error);