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

content/renderer/device_motion_event_pump.h

Index: content/renderer/device_motion_event_pump.h
diff --git a/content/renderer/device_motion_event_pump.h b/content/renderer/device_motion_event_pump.h
new file mode 100644
index 0000000000000000000000000000000000000000..f118fd2abe47e59333d7c4fdabc8da660c38215e
--- /dev/null
+++ b/content/renderer/device_motion_event_pump.h
@@ -0,0 +1,52 @@
+// 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.
+
+#ifndef CONTENT_RENDERER_DEVICE_MOTION_EVENT_PUMP_H_
+#define CONTENT_RENDERER_DEVICE_MOTION_EVENT_PUMP_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "base/shared_memory.h"
+#include "base/time.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebDeviceMotionHandler.h"
+
+namespace WebKit {
+class WebDeviceMotionData;
+class WebDeviceMotionListener;
+}
+
+namespace content {
+
+class DeviceMotionSharedMemoryReader;
+
+class DeviceMotionEventPump : public WebKit::WebDeviceMotionHandler {
+ public:
+  DeviceMotionEventPump();
+  virtual ~DeviceMotionEventPump();
+
+  // Delay between subsequent firing of events.
+  const static double pump_delay_millis = 40;

[jamesr, 2013/05/16 19:53:06]

put the definition in a translation unit or you'll get multiple copies. why does
this have to be public?

[timvolodine, 2013/05/20 18:18:48]

Done.

+
+  // Sets the listener to receive updates for device motion data at
+  // regular intervals.
+  virtual void startListeningToDeviceMotion(
+      WebKit::WebDeviceMotionListener*) OVERRIDE;
+
+  // Removes the current listener after which it will not receive any updates.
+  virtual void stopListeningToDeviceMotion() OVERRIDE;
+
+ private:
+  WebKit::WebDeviceMotionListener* listener_;
+
+  void fire();
+  bool shouldFireEvent(WebKit::WebDeviceMotionData&);
+
+  bool fire_pending_;
+  base::TimeTicks last_fire_event_time_;
+  scoped_ptr<DeviceMotionSharedMemoryReader> reader_;
+  base::TimeDelta pump_delay_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_DEVICE_MOTION_EVENT_PUMP_H_