Re-enable testScrollAction telemetry unit test.

BUG=308846

Review URL: https://codereview.chromium.org/34753005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230731 0039d316-1c4b-4281-b951-d872f2087c98
Rename GestureEventFilter "async" events to "events ignoring ack."
BUG=306562

Review URL: https://codereview.chromium.org/35583002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230732 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230732