GitLab

Prior to this CL, the root damage rect might have partially
intersected child render passes that had backdrop filters applied.
In that case, the backdrop filter code would attempt to read back
the backdrop image, and would find already-filtered content outside
of the damage rect, but inside the render pass quad bounds. It would
then filter this image, and if the backdrop filters moved pixels,
some of that double-filtered content would bleed back into the damage
rect and be used. This would lead to visual artifacts.

With this CL, any child render passes that contain pixel-moving
backdrop filters are checked for intersection with the root damage
rect, and if they intersect, the damage rect is expanded to include
the entire child render pass output rect.

Bug: 986206
Change-Id: I81a51e24548cae736172938ce190f6ba4c6d2b94
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1847675
Commit-Queue: Mason Freed <masonfreed@chromium.org>
Reviewed-by: Eric Karl <ericrk@chromium.org>
Reviewed-by: kylechar <kylechar@chromium.org>
Auto-Submit: Mason Freed <masonfreed@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706531}