Implement the content/renderer and content/browser part of the Device Motion API.

content/browser/device_orientation/device_motion_provider.cc

+// Copyright (c) 2013 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 "base/logging.h"
+#include "content/browser/device_orientation/device_motion_provider.h"
+#include "content/common/device_motion_hardware_buffer.h"
+
+namespace content {
+
+DeviceMotionProvider::DeviceMotionProvider()
+    : is_started_(false) {
+  size_t data_size = sizeof(DeviceMotionHardwareBuffer);
+  bool res = device_motion_shared_memory_.CreateAndMapAnonymous(data_size);
+  CHECK(res);

[palmer, 2013/07/10 18:23:48]

Should the browser really crash in this case? I suppose it's probably going to
die soon anyway, if this fails, but I want to make sure that's what you intend.

[timvolodine, 2013/07/10 21:17:50]

hmm, yes it will die in this case. I've added a comment to look into possibly
making this non-fatal.

+  DeviceMotionHardwareBuffer* hwbuf = SharedMemoryAsHardwareBuffer();
+  memset(hwbuf, 0, sizeof(DeviceMotionHardwareBuffer));
+}
+
+DeviceMotionProvider::~DeviceMotionProvider() {
+}
+
+base::SharedMemoryHandle DeviceMotionProvider::GetSharedMemoryHandleForProcess(
+    base::ProcessHandle process) {
+  base::SharedMemoryHandle renderer_handle;
+  device_motion_shared_memory_.ShareToProcess(process, &renderer_handle);
+  return renderer_handle;
+}
+
+void DeviceMotionProvider::StartFetchingDeviceMotionData() {
+  if (is_started_)
+    return;
+  // FIXME: call data_fetcher_->StartFetchingDeviceMotionData(
+  // SharedMemoryAsHardwareBuffer());
+  is_started_ = true;
+}
+
+void DeviceMotionProvider::StopFetchingDeviceMotionData() {
+  // FIXME: call data_fetcher_->StopFetchingDeviceMotionData();
+  is_started_ = false;
+}
+
+DeviceMotionHardwareBuffer* DeviceMotionProvider::
+    SharedMemoryAsHardwareBuffer() {
+  void* mem = device_motion_shared_memory_.memory();
+  CHECK(mem);
+  return static_cast<DeviceMotionHardwareBuffer*>(mem);
+}
+
+}  // namespace content