Move TransformingTouchDelegate logic to BaseContainerView.

In ag/1460444 we used TransformingTouchDelegate to extend the
touch target for the widgets list. Now both WidgetsContainerView
and AllAppsContainerView will use the same TransformingTouchDelegate logic
to extend the touch target for their respective lists.

This is part of a larger refactor where in a follow up CL, we will
handle the logic for dismissing WCV and AACV when touching outside
of its content in BaseContainerView. (currently broken in WCV).

Change-Id: I7fddb456bba34a6533f8824da0481d308a8b715e
3 files changed