Implement Device Orientation using shared memory in content/renderer.

content/browser/device_orientation/device_motion_message_filter.cc

Index: content/browser/device_orientation/device_motion_message_filter.cc
diff --git a/content/browser/device_orientation/device_motion_message_filter.cc b/content/browser/device_orientation/device_motion_message_filter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3c619c6cd163d8bcf66652f039c8de5fad957890
--- /dev/null
+++ b/content/browser/device_orientation/device_motion_message_filter.cc
@@ -0,0 +1,61 @@
+// Copyright 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 "content/browser/device_orientation/device_motion_message_filter.h"
+
+#include "content/browser/device_orientation/device_motion_service.h"
+#include "content/common/device_orientation/device_motion_messages.h"
+
+namespace content {
+
+DeviceMotionMessageFilter::DeviceMotionMessageFilter()
+    : is_started_(false) {
+}
+
+DeviceMotionMessageFilter::~DeviceMotionMessageFilter() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  if (is_started_)
+    DeviceMotionService::GetInstance()->RemoveConsumer();
+}
+
+bool DeviceMotionMessageFilter::OnMessageReceived(
+    const IPC::Message& message,
+    bool* message_was_ok) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP_EX(DeviceMotionMessageFilter,
+                           message,
+                           *message_was_ok)
+    IPC_MESSAGE_HANDLER(DeviceMotionHostMsg_StartPolling,
+                        OnDeviceMotionStartPolling)
+    IPC_MESSAGE_HANDLER(DeviceMotionHostMsg_StopPolling,
+                        OnDeviceMotionStopPolling)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP_EX()
+  return handled;
+}
+
+void DeviceMotionMessageFilter::OnDeviceMotionStartPolling() {
+  DCHECK(!is_started_);
+  if (is_started_)
+    return;
+  is_started_ = true;
+  DeviceMotionService::GetInstance()->AddConsumer();
+  DidStartDeviceMotionPolling();
+}
+
+void DeviceMotionMessageFilter::OnDeviceMotionStopPolling() {
+  DCHECK(is_started_);
+  if (!is_started_)
+    return;
+  is_started_ = false;
+  DeviceMotionService::GetInstance()->RemoveConsumer();
+}
+
+void DeviceMotionMessageFilter::DidStartDeviceMotionPolling() {
+  Send(new DeviceMotionMsg_DidStartPolling(
+      DeviceMotionService::GetInstance()->GetSharedMemoryHandleForProcess(
+          PeerHandle())));
+}
+
+}  // namespace content