Implement the Blink part of the Device Motion API.

public/platform/WebDeviceMotionListener.h

Index: public/platform/WebDeviceMotionListener.h
diff --git a/public/platform/WebDeviceMotionListener.h b/public/platform/WebDeviceMotionListener.h
new file mode 100644
index 0000000000000000000000000000000000000000..b8da1500d6afa8f7c97bb38454effb119de1a4a2
--- /dev/null
+++ b/public/platform/WebDeviceMotionListener.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2013 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
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef WebDeviceMotionListener_h
+#define WebDeviceMotionListener_h
+
+namespace WebKit {
+
+class WebDeviceMotionData;
+
+class WebDeviceMotionListener {
+public:
+    // This method is called every time new device motion data is available.
+    virtual void didChangeDeviceMotion(const WebDeviceMotionData&) = 0;
+};
+
+} // namespace WebKit
+
+#endif // WebDeviceMotionListener_h