commit 2b45a16b8b0f46090c0e612ef8a3d6084997fc27
author Chet Haase <chet@google.com> Fri Jul 11 13:38:51 2014 -0700
committer Chet Haase <chet@google.com> Fri Jul 11 13:38:51 2014 -0700
tree 8d1c837afd95400f3bf1625224e5bef7c72538ab
parent c09a04da297ff85b97aa6ec0a457e9292b8bf7fa

Optimize gatherTransparentRegions to account for transparent bg

gatherTransparentRegions() incorrectly takes the background into account
even when that background drawable is a completely transparent ColorDrawable
(which you can get by calling View.setBackgroundColor(0)). Checking
the opacity of the drawable allows us to ignore drawables that are not
visible.

Issue #13465427 Performance suggestion: View.setBackgroundColor(0) should set background to null

Change-Id: Ic552bf6a07cc9229fd32febc3ada73a0701cad0c