Fix saveLayer() with a pixel-moving filter vs SkBBoxHierarchyRecord / SkRecordDraw

Fix saveLayer() with a pixel-moving filter vs SkBBoxHierarchyRecord / SkRecordDraw

In SkBBoxHierarchyRecord:
  Since the bounds we pass to saveLayer are in the pre-filtering
  coordinate space, they aren't correct for determining the actual
  device pixels touched by the saveLayer in this case.

  The easiest fix for now is to pass the clip bounds, since the final
  draw done in restore() will never draw outside the clip.

In SkRecordDraw:
  We do adjust the bounds passed to saveLayer, so we just need to make
  sure that when we're using a paint that may affect transparent black,
  we ignore the calculated bounds of draw ops and use the clip intersected
  with those adjusted bounds.

See originally crrev.com/497773002

BUG=skia:
R=reed@google.com, senorblanco@chromium.org, junov@chromium.org, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/496963003

(cherry picked from commit d910f544439fffa6c2bcc5181b79b2811a4c130a)

Committed: https://skia.googlesource.com/skia/+/749e42a

[Stephen White, 2014-08-26 21:31:08]

Committed patchset #1 manually as 749e42a (presubmit successful).