90b6e48793
This CL is the first in a series of CL's that will extract the zoom code from WebView and put it into ZoomManager. This initial CL only extracts the on-screen zoom controls and required variables into the ZoomManager. Since the on-screen controls are well defined I put them into their own class called ZoomControls. All of WebView's zoom interactions are handled by the ZoomManager. The ZoomManager can then handle the request internally or as in the case of on-screen controls pass the request to another class. Change-Id: Icfc91ed0456c88d633249c26b9afc7dd216f75a1 http://b/2671604