Additions to the Android java-side Device Motion/Orientation fetching

A number of small modifications/improvements:
- add a getNumberActiveMotionSensors() to determine how many sensors could actually be activated for device motion
- make sure that the orientation events are only fired when the appropriate sensors change
- rename mAccelerationVector to mAccelerationIncludingGravityVector

BUG=135804

Review URL: https://chromiumcodereview.appspot.com/15817019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@206091 0039d316-1c4b-4281-b951-d872f2087c98
4 files changed