Add DidStopFlinging support for TouchSelection Editing in OOPIFs.

This CL adds handlers to notify RenderWidgetHostViewChildFrame and its
TouchSelectionControllerClientChildFrame when main-thread flings complete
in an oopif renderer.

This is necessary for correct operation of the touch selection editing
handles during touch scroll.

Bug: 756184
Change-Id: Ibb4cff0e09119c5c95cd36d6f3ab6737a59be7b3
Reviewed-on: https://chromium-review.googlesource.com/647827
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: James MacLean <wjmaclean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#499294}
9 files changed