installPixels returns true if null-pixels -- devolving to setConfig

fixes assumptions in chrome's ui_unittests: RenderTextTest.SelectionKeepsLigatures

R=robertphillips@google.com, bsalomon@google.com

Author: reed@google.com

Review URL: https://codereview.chromium.org/170713006

git-svn-id: http://skia.googlecode.com/svn/trunk@13492 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed