Add plumbing for platform based Device Motion testing.

This CL implements injection of a mock WebDeviceMotionData into the Platform for testing purposes. Once the mock WebDeviceMotionData is set it will be returned as a one-shot event once Blink registers its DeviceMotionListener through the platform using setDeviceMotionListener method.

BUG=135804

Review URL: https://chromiumcodereview.appspot.com/5222955109842944

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@212084 0039d316-1c4b-4281-b951-d872f2087c98
6 files changed