http://b/issue?id=3378224
This is a simple unhide.
Allow the use of WebView pinch-to-zoom gestures
without the on screen zoom controls.
Currently, enabling pinch to zoom with the public API also shows the
on screen zoom buttons.
If the zoom buttons are not wanted, a custom implementation of pinch to
zoom is required, which can't be done correctly at this point.
Change-Id: I3f94080471c3a4b498b11c91603fff9994dc3c2c
5840cd294a