Content and viewport rects set in one step.

 Bug 5342918
 The content rect of the WebView was being retrieved during
 the draw while the viewport rect was being set when the
 draw functor was setup. During animations, the content
 rect was changing between the time the draw functor was
 retrieved and it was executed. The content rect is now
 being set with the viewport rect.

 Wekbkit Change: I05d68dcc

Change-Id: I1b0978eeb27d9f1deddfeba3ede869f735f74394