suppress partial screen updates if a canvas element is visible

A PictureSet contains a list of pictures. Each picture draws
part of the screen. If the picture contains a Canvas element,
the corresponding bitmap is not shared.

Small partial invalidates can create a dozen or so pictures,
each of which may be quite small, a few hundred bytes. But
the bitmap referenced by the picture may be large, several
meg.

The backing bitmap is unique to the Canvas element. Since
a canvas rarely benefits from small updates, disable the
partial invalidates if CacheBuilder detects a canvas.

Change-Id: I5761667db3d037d7363dcb01f8a26f7f62e2eabc
http://b/2678787

0 files changed, 0 insertions, 0 deletions