eoving Zoom animation logic from WebView into ZoomManager. This is

pick bad5ede Revert "Refactor the on-screen zoom controls into a separate class."

one part of a series of CL's that is intended to refactor all zoom
logic into the ZoomManager.

Change-Id: I6260c7d2daade4861df1296c9db364ee2a892bd0
http://b/2671604