Bug: 6490959
The issue here is that if the page calls preventDefault on a
touchstart handler WebViewClassic will not do a HIT_TEST as it
doesn't get the ACTION_DOWN. This means that the mouse is in the
wrong position when the click ultimately fires.
This changes it so that WebViewInputDispatcher will always do a
HIT_TEST at the start of a touch stream, which ensures that the
mouse is positioned correctly.
Change-Id: I1aaca7692e2c7aeedeb21fa3592cd4cb3223ea25
41f73bdf4d