fixing problem with allocating too much memory to a surface by fixing

the size of the surface when it exceeds a threshold and resizing the
surface when it falls beneath the threshold.

This change also causes the surface to fix its size while it is
being zoomed in order to prevent the surface from getting multiple
surfaceChangedEvents as the result of a zoom.  This also allows us
to have a smooth zoom animation for the surface.

Change-Id: I30e208f98d3a32660032bf1df9de77d0a813d756