Fix recursive computation of filter bounds for drop shadow,
morphology, blur.
[Reland with fixed tests.]
Because we're computing "backwards" from a clip rect of destination
pixels to be filled to the required source pixels, we should use tail
recursion rather than head recursion in onFilterBounds().
This actually only makes a difference for drop-shadow, where
the computation is non-commutative. Blur and morphology commute, but I
moved them to tail recursion anyway for clarity (so all onFilterBounds
use tail recursion).
BUG=skia:
R=bsalomon@google.com
Author: senorblanco@chromium.org
Review URL: https://codereview.chromium.org/481273005
4 files changed