1. Reposition the toolbar on predraw only when positioning has changed.
2. Update the toolbar popup's position only if the content rect changed.
3. Fix FloatingToolbarPopup.cancelOverflowAnimations().
The previous implementation wasn't actually cancelling the animation.
(1) is enough to fix the bug. But (2) and (3) fix issues in the
toolbar directly related to this bug.
Bug: 22039189
Change-Id: I84ec793d788f9402a1f8635e68e3344746f6af07
c107b0ecdc