Clean up from earlier changes to place title bar at top of WebView

Rename addTitleBar to setEmbeddedTitleBar.  This requires a change
to packages/apps/Browser.  Also remove mTitleBar if there already
was one.

In ViewManager, call contentToViewDimension where appropriate.

Change-Id: If4d378fad192990253411924a9a80bee96e63ff2