tree 9236b8acd8ef7ca0f7ee33bded19532c1b7833fc
parent a7f4c435bc1dcd845990a5515828bbe8cccfab41
author senorblanco <senorblanco@chromium.org> 1440081731 -0700
committer Commit bot <commit-bot@chromium.org> 1440081731 -0700

Implement canComputeFastBounds() for image filters.

Image filters have never implemented this check, which means that
filters which affect transparent black falsely claim they can compute
their bounds.

Implemented an affectsTransparentBlack() virtual for image
filters, and a similar helper function for color filters.

This will affect the following GMs: imagefiltersscaled
(lighting, perlin noise now filter to clip),
colorfilterimagefilter (new test case), imagefiltersclipped
(perlin noise now filters to clip).

Note: I de-inlined SkPaint::canComputeFastBounds() to avoid adding
a dependency from SkPaint.h to SkImageFilter.h.h. Skia benches show
no impact from this change, but will watch the perf bots carefully.

BUG=4212

Review URL: https://codereview.chromium.org/1296943002