Add plumbing for testing API for MockWebDeviceMotionHandler injection.

content/shell/renderer/webkit_test_runner.cc

Index: content/shell/renderer/webkit_test_runner.cc
diff --git a/content/shell/renderer/webkit_test_runner.cc b/content/shell/renderer/webkit_test_runner.cc
index 07e906d8fa5c13903aa5d7d113b49437e4782ae0..c2ebe2ed4268d0fa699d54dbbef226e4af8e8347 100644
--- a/content/shell/renderer/webkit_test_runner.cc
+++ b/content/shell/renderer/webkit_test_runner.cc
@@ -65,6 +65,7 @@ using WebKit::Platform;
 using WebKit::WebArrayBufferView;
 using WebKit::WebContextMenuData;
 using WebKit::WebDevToolsAgent;
+using WebKit::WebDeviceMotionListener;
 using WebKit::WebDeviceOrientation;
 using WebKit::WebElement;
 using WebKit::WebFrame;
@@ -212,6 +213,11 @@ void WebKitTestRunner::setGamepadData(const WebGamepads& gamepads) {
   SetMockGamepads(gamepads);
 }
 
+void WebKitTestRunner::setDeviceMotionListener(
+    WebDeviceMotionListener* listener) {
+  SetMockDeviceMotionListener(listener);
+}
+
 void WebKitTestRunner::printMessage(const std::string& message) {
   Send(new ShellViewHostMsg_PrintMessage(routing_id(), message));
 }