Migrating majority of gamepad from content/browser/ to device/

content/browser/gamepad/gamepad_shared_buffer_impl.cc

+// Copyright 2016 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/browser/gamepad/gamepad_shared_buffer_impl.h"
+
+#include "content/common/gamepad_hardware_buffer.h"
+
+namespace content {
+
+GamepadSharedBufferImpl::GamepadSharedBufferImpl() {
+  size_t data_size = sizeof(GamepadHardwareBuffer);
+  bool res = shared_memory_.CreateAndMapAnonymous(data_size);
+  CHECK(res);
+  GamepadHardwareBuffer* hwbuf = hardware_buffer();
+  memset(hwbuf, 0, sizeof(GamepadHardwareBuffer));

[piman, 2016/06/22 22:52:59]

nit: use placement new? GamepadHardwareBuffer is not an aggregate/POD, so
accessing without constructing is undefined behavior.

+}
+
+GamepadSharedBufferImpl::~GamepadSharedBufferImpl() {
+
+}
+
+base::SharedMemory* GamepadSharedBufferImpl::shared_memory() {
+  return &shared_memory_;
+}
+
+blink::WebGamepads* GamepadSharedBufferImpl::buffer() {
+  return &(hardware_buffer()->buffer);
+}
+
+GamepadHardwareBuffer* GamepadSharedBufferImpl::hardware_buffer() {
+  void* mem = shared_memory_.memory();
+  CHECK(mem);

[piman, 2016/06/22 22:52:59]

nit: DCHECK

+  return static_cast<GamepadHardwareBuffer*>(mem);
+}
+
+void GamepadSharedBufferImpl::WriteBegin() {
+  hardware_buffer()->sequence.WriteBegin();
+}
+
+void GamepadSharedBufferImpl::WriteEnd() {
+  hardware_buffer()->sequence.WriteEnd();
+}
+
+}  // namespace content