[Android] Looks for events injected to signal passing monkey test.

BUG=303412
R=craigdh@chromium.org

Review URL: https://codereview.chromium.org/26071002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227138 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227138