Using mojo::ScopedSharedBufferHandle directly in GamepadSharedMemoryReader

content/renderer/gamepad_shared_memory_reader.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/gamepad_shared_memory_reader.h"
 
 #include "base/metrics/histogram_macros.h"
 #include "base/trace_event/trace_event.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/renderer/renderer_blink_platform_impl.h"
@@ skipping 11 matching lines @@
       binding_(this) {
   if (thread) {
     thread->GetRemoteInterfaces()->GetInterface(
         mojo::GetProxy(&gamepad_monitor_));
     gamepad_monitor_->SetObserver(binding_.CreateInterfacePtrAndBind());
   }
 }
 
 void GamepadSharedMemoryReader::SendStartMessage() {
   if (gamepad_monitor_) {
-    mojo::ScopedSharedBufferHandle buffer_handle;
-    gamepad_monitor_->GamepadStartPolling(&buffer_handle);
-    // TODO(heke): Use mojo::SharedBuffer rather than base::SharedMemory. See
-    // crbug.com/670655.
-    MojoResult result = mojo::UnwrapSharedMemoryHandle(
-        std::move(buffer_handle), &renderer_shared_memory_handle_, nullptr,
-        nullptr);
-    CHECK_EQ(MOJO_RESULT_OK, result);
+    gamepad_monitor_->GamepadStartPolling(&renderer_shared_buffer_handle_);
   }
 }
 
 void GamepadSharedMemoryReader::SendStopMessage() {
   if (gamepad_monitor_) {
     gamepad_monitor_->GamepadStopPolling();
   }
 }
 
 void GamepadSharedMemoryReader::Start(
     blink::WebPlatformEventListener* listener) {
   PlatformEventObserver::Start(listener);
 
   // If we don't get a valid handle from the browser, don't try to Map (we're
   // probably out of memory or file handles).
-  bool valid_handle = base::SharedMemory::IsHandleValid(
-      renderer_shared_memory_handle_);
+  bool valid_handle = renderer_shared_buffer_handle_.is_valid();
   UMA_HISTOGRAM_BOOLEAN("Gamepad.ValidSharedMemoryHandle", valid_handle);
   if (!valid_handle)
     return;
 
-  renderer_shared_memory_.reset(
-      new base::SharedMemory(renderer_shared_memory_handle_, true));
-  CHECK(renderer_shared_memory_->Map(sizeof(GamepadHardwareBuffer)));
-  void *memory = renderer_shared_memory_->memory();
+  renderer_shared_buffer_mapping_ =
+      renderer_shared_buffer_handle_->Map(sizeof(GamepadHardwareBuffer));
+  CHECK(renderer_shared_buffer_mapping_);
+  void* memory = renderer_shared_buffer_mapping_.get();
   CHECK(memory);
   gamepad_hardware_buffer_ =
       static_cast<GamepadHardwareBuffer*>(memory);
 }
 
 void GamepadSharedMemoryReader::SampleGamepads(blink::WebGamepads& gamepads) {
   // Blink should have started observing at that point.
   CHECK(is_observing());
 
   // ==========
   //   DANGER
   // ==========
   //
   // This logic is duplicated in Pepper as well. If you change it, that also
   // needs to be in sync. See ppapi/proxy/gamepad_resource.cc.
   blink::WebGamepads read_into;
   TRACE_EVENT0("GAMEPAD", "SampleGamepads");
 
-  if (!base::SharedMemory::IsHandleValid(renderer_shared_memory_handle_))
+  if (!renderer_shared_buffer_handle_.is_valid())
     return;
 
   // Only try to read this many times before failing to avoid waiting here
   // very long in case of contention with the writer. TODO(scottmg) Tune this
   // number (as low as 1?) if histogram shows distribution as mostly
   // 0-and-maximum.
   const int kMaximumContentionCount = 10;
   int contention_count = -1;
   base::subtle::Atomic32 version;
   do {
@@ skipping 40 matching lines @@
 }
 
 void GamepadSharedMemoryReader::GamepadDisconnected(
     int index,
     const blink::WebGamepad& gamepad) {
   if (listener())
     listener()->didDisconnectGamepad(index, gamepad);
 }
 
 } // namespace content