Implement SkPictureImageFilter bounds computation.

SkPictureImageFilter::onFilterBounds() was unimplemented, causing
incorrect results for SVG filters and impl-side painting (see Chrome
bug https://code.google.com/p/chromium/issues/detail?id=375162).

BUG=skia:
R=reed@google.com

Review URL: https://codereview.chromium.org/306733003

git-svn-id: http://skia.googlecode.com/svn/trunk/include@15003 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed