Target touches to the correct display.

ui::TouchEvents now know the id of their source device.
The target of a touch can't be effected by a touch on another display.

Relanding https://codereview.chromium.org/103173004/, after it was
reverted https://codereview.chromium.org/103173004. When ensuring that
the GR wasn't reused between tests, I had neglected to delete the old
GR.

BUG=315651
TEST=GestureRecognizerTest.GestureEventTouchLockIgnoresOtherScreens

Review URL: https://codereview.chromium.org/132123004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244220 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 244220