Linear-time implementation of willPlaybackBitmaps(), computed & cached
on construction in SkPicture. Unit test.

Template trickery thanks to mtklein@.

BUG=skia:2702
R=mtklein@google.com, reed@android.com, reed@google.com, tomhudson@google.com, mtklein, reed

Author: tomhudson@chromium.org

Review URL: https://codereview.chromium.org/366443002
6 files changed