[blink] Skip ancestor clip in PaintLayerPainter for squashed layers.

[blink] Skip ancestor clip in PaintLayerPainter for squashed layers.

The squashing layer passed a differrent painting root that is not the same
as the backing's space when painting squashed layers, thus a wrong clip
is applied when squashed layers are painted.

This was not a problem prior to GeometryMapper-based PaintLayerClipper
because the non-GM PaintLayerClipper skipped visual rect optimization
in this particular corner case.

BUG=712783
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Review-Url: https://codereview.chromium.org/2830013007
Cr-Commit-Position: refs/heads/master@{#467220}
(cherry picked from commit fb28c1b7511ceeb4d47ed42dbeb0676591469fe6)

Review-Url: https://codereview.chromium.org/2843223003 .
Cr-Commit-Position: refs/branch-heads/3071@{#242}
Cr-Branched-From: a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed: https://chromium.googlesource.com/chromium/src/+/840427fa341fe9f413fdf5c7df1941f08e152380

[trchen, 2017-04-26 23:51:04]

Description was changed from

==========
[blink] Skip ancestor clip in PaintLayerPainter for squashed layers.

The squashing layer passed a differrent painting root that is not the same
as the backing's space when painting squashed layers, thus a wrong clip
is applied when squashed layers are painted.

This was not a problem prior to GeometryMapper-based PaintLayerClipper
because the non-GM PaintLayerClipper skipped visual rect optimization
in this particular corner case.

BUG=712783
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Review-Url: https://codereview.chromium.org/2830013007
Cr-Commit-Position: refs/heads/master@{#467220}
(cherry picked from commit fb28c1b7511ceeb4d47ed42dbeb0676591469fe6)
==========

to

==========
[blink] Skip ancestor clip in PaintLayerPainter for squashed layers.

The squashing layer passed a differrent painting root that is not the same
as the backing's space when painting squashed layers, thus a wrong clip
is applied when squashed layers are painted.

This was not a problem prior to GeometryMapper-based PaintLayerClipper
because the non-GM PaintLayerClipper skipped visual rect optimization
in this particular corner case.

BUG=712783
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Review-Url: https://codereview.chromium.org/2830013007
Cr-Commit-Position: refs/heads/master@{#467220}
(cherry picked from commit fb28c1b7511ceeb4d47ed42dbeb0676591469fe6)

Review-Url: https://codereview.chromium.org/2843223003 .
Cr-Commit-Position: refs/branch-heads/3071@{#242}
Cr-Branched-From:
a106f0abbf69dad349d4aaf4bcc4f5d376dd2377-refs/heads/master@{#464641}
Committed:
https://chromium.googlesource.com/chromium/src/+/840427fa341fe9f413fdf5c7df19...
==========

[trchen, 2017-04-26 23:51:06]

Committed patchset #1 (id:1) manually as
840427fa341fe9f413fdf5c7df1941f08e152380.