overscroll: Fix an issue where the overscroll window could get stuck.
While the content page is still loading after a gesture navigation, the overlay
that shows the preview of the history page should not forward input events to
the content page. Forwarding events during this time can get the overscroll
controller into an inconsistent state (because the overscroll controller does
not receive the whole stream of events after the overlay window is destroyed).
BUG=174186
Review URL: https://codereview.chromium.org/12346002
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@184660 0039d316-1c4b-4281-b951-d872f2087c98
3 files changed
