tree 610821e20323677aef80dc2a3a0db5aaf6a55603
parent c6da2a903784020b4d3c6f810340bedf130c7ea0
author Tien-Ren Chen <trchen@chromium.org> 1445466683 -0700
committer Tien-Ren Chen <trchen@chromium.org> 1445467116 +0000

Invalidate background-attachment:fixed on scroll.

If there is any slow repaint objects (i.e. background-attachment:fixed),
we fall back to the FrameView::scrollContentsSlowPath() that invalidates
the whole main graphics layer. However this is not correct because the
object is not necessarily backed by the main backing. We should invalidate
them individually.

Note: This approach is still not entirely correct. With composited overflow
scrolling, we should inhibit threaded scrolling when a slow repaint descandant
presents and do similar invalidation. This is non-trivial to implement.
As the old compositing architecture is deprecated anyway, we will try to fix
the issue with SPv2.

BUG=540499

Review URL: https://codereview.chromium.org/1394193003

Cr-Commit-Position: refs/heads/master@{#354960}
(cherry picked from commit 1d3aacc9cd5028db3a36036bfbace8933097be00)

Review URL: https://codereview.chromium.org/1419823005 .

Cr-Commit-Position: refs/branch-heads/2526@{#201}
Cr-Branched-From: cb947c0153db0ec02a8abbcb3ca086d88bf6006f-refs/heads/master@{#352221}