Fix filter bounds computation for SkOffsetImageFilter.

SkOffsetImageFilter::onFilterBounds() was not recursing into its input
filter when computing bounds.

BUG=374556
R=junov@chromium.org

Review URL: https://codereview.chromium.org/304743003

git-svn-id: http://skia.googlecode.com/svn/trunk@14928 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed