Implement the Blink part of the Device Motion API.

public/platform/Platform.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 36 matching lines @@
 
 class GrContext;
 
 namespace WebKit {
 
 class WebAudioBus;
 class WebBlobRegistry;
 class WebClipboard;
 class WebCompositorSupport;
 class WebCookieJar;
+class WebDeviceMotionListener;
 class WebDiscardableMemory;
 class WebFallbackThemeEngine;
 class WebFileSystem;
 class WebFileUtilities;
 class WebFlingAnimator;
 class WebGestureCurveTarget;
 class WebGestureCurve;
 class WebGraphicsContext3DProvider;
 class WebHyphenator;
 class WebMediaStreamCenter;
@@ skipping 436 matching lines @@
 
     // May return null if WebRTC functionality is not avaliable or out of resources.
     virtual WebMediaStreamCenter* createMediaStreamCenter(WebMediaStreamCenterClient*) { return 0; }
 
 
     // WebWorker ----------------------------------------------------------
 
     virtual void didStartWorkerRunLoop(const WebWorkerRunLoop&) { }
     virtual void didStopWorkerRunLoop(const WebWorkerRunLoop&) { }
 
+
+    // Device Motion / Orientation ----------------------------------------
+
+    // Sets a Listener to listen for device motion data updates.
+    // If null, the platform stops providing device motion data to the current listener.
+    virtual void setDeviceMotionListener(WebKit::WebDeviceMotionListener*) { }
+
 protected:
     virtual ~Platform() { }
 };
 
 } // namespace WebKit
 
 #endif