WebKit & WebCore part of the device motion implementation using the platform layer.

Source/Platform/chromium/public/WebDeviceMotionReader.h

+/*
+ * 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 WebDeviceMotionReader_h
+#define WebDeviceMotionReader_h
+
+#include "WebDeviceMotionData.h"
+
+namespace WebKit {
+
+// FIXME: abstract this into a common superclass, to be used with device orientation as well.

[eseidel, 2013/04/23 15:21:24]

I'm not particularly familiar with Platform.  abarth/mpilgrim know it much
better than I.

[timvolodine, 2013/04/23 18:10:40]

ok will try to ask them.

+class WebDeviceMotionReader {
+public:
+    WebDeviceMotionReader() { }
+    virtual ~WebDeviceMotionReader() { }
+
+    // Returns true if successfully filled the WebDeviceMotionData object with the latest motion data.
+    // Returns false if there is no device motion data available.
+    virtual bool latestDeviceMotionData(WebDeviceMotionData&) = 0;
+
+    // Starts providing motion data. This method should be called before any calls to latestDeviceMotionData.
+    virtual void startUpdating() = 0;
+
+    // Indicates that this reader will not be used to fetch data anymore, so it can stop providing motion data.
+    virtual void stopUpdating() = 0;
+};
+
+} // namespace WebKit
+
+#endif // WebDeviceMotionReader_h