Fix mouse lock on chromeos
* CompoundEventFilter should show cursor only if the cursor was hidden by this event filter.
* CompoundEventFilter shouldn't try to hide if it's already hidden by someone else.
* It no longer needs set_update_cursor_visibility.
* There is one edge case where it leaves cursor visible. Cursor is hidden by the CompoundEventFilter, then again hidden by mouse lock. I changed RWHVA to hide the cursor if it's visible when mouse is moved.

BUG=152319
TEST=updated test case. also tested manually: see bug for repro step.

Review URL: https://chromiumcodereview.appspot.com/10982040

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@158845 0039d316-1c4b-4281-b951-d872f2087c98
7 files changed