Implement the Blink part of the Device Motion API.

Tools/DumpRenderTree/chromium/TestRunner/public/WebTestDelegate.h

Index: Tools/DumpRenderTree/chromium/TestRunner/public/WebTestDelegate.h
diff --git a/Tools/DumpRenderTree/chromium/TestRunner/public/WebTestDelegate.h b/Tools/DumpRenderTree/chromium/TestRunner/public/WebTestDelegate.h
index 1897f55d3e8f09147f2f09f10fafceeb241a3b5e..a009a4a012390c9d354639a06560c9428904b9ba 100644
--- a/Tools/DumpRenderTree/chromium/TestRunner/public/WebTestDelegate.h
+++ b/Tools/DumpRenderTree/chromium/TestRunner/public/WebTestDelegate.h
@@ -39,6 +39,7 @@
 #define WEBTESTRUNNER_NEW_HISTORY_CAPTURE
 
 namespace WebKit {
+class WebDeviceMotionHandler;
 class WebFrame;
 class WebGamepads;
 class WebHistoryItem;
@@ -64,6 +65,9 @@ public:
     // Set the gamepads to return from Platform::sampleGamepads().
     virtual void setGamepadData(const WebKit::WebGamepads&) = 0;
 
+    // Set the WebDeviceMotionHandler to return from Platform::deviceMotionHandler().
+    virtual void setDeviceMotionHandler(WebKit::WebDeviceMotionHandler*) { };
+
     // Add a message to the text dump for the layout test.
     virtual void printMessage(const std::string& message) = 0;