Re-land: Make GraphicsLayer the DisplayItemClient for scrollbars composited via PaintLayerComposito…

Re-land: Make GraphicsLayer the DisplayItemClient for scrollbars composited via PaintLayerCompositor.

Updated to deal gracefully with potentially null picture recording in
performance testing.

Original change description:

Currently, the DisplayItemClient is LayoutScrollbarPart. This has two
problems: the mapping between the LayoutScrollbarPart and its backing
is hard to reverse-engineer given the way the scrollbar code is set
up (LayoutScrollbarPart vs Scrollbar vs ScrollableArea), and the
fact that LayoutScrollbarPart can be painted in both non-composited
and composited modes. This distinction is important for computation
of correct visual rects.

This can be cleaned up by replaying the painted scrollbar content
with the GraphicsLayer backing as the DisplayItemClient, which
has the correct visualRect() (i.e. bounds of GraphicsLayer).

BUG=529938
Committed: https://crrev.com/8460ef8fc6125185abc1486eb61b0ca7fc9298ad
Cr-Commit-Position: refs/heads/master@{#382778}

patch from issue 1825193002 at patchset 100001 (http://crrev.com/1825193002#ps100001)

TBR=chrishtr

Committed: https://crrev.com/7bd3f083b468f3ae88ac48ca9cdbaa918d148cbb
Cr-Commit-Position: refs/heads/master@{#384070}

[wkorman, 2016-03-30 18:19:00]

wkorman@chromium.org changed reviewers:
+ chrishtr@chromium.org, fmalita@chromium.org

[wkorman, 2016-03-30 18:19:01]

Follow-up to http://crrev.com/1841833002. Will conflict with merge of fmalita@
http://crrev.com/1849433002. If this lands first, fmalita@ will need to modify
PaintLayerCompositor.cpp:835 to go back to assumed non-null picture.

Open to landing order, sending as-is since fmalita@ change is still in
discussion and landing time is TBD.

We should also consider some way to execute a meaningful chunk of code base with
GraphicsContext::FullyDisabled in a test that's part of the CQ to prevent
accidental breakage of cluster telemetry benchmarks in future.

[wkorman, 2016-03-30 18:34:56]

The CQ bit was checked by wkorman@chromium.org

[wkorman, 2016-03-30 18:34:56]

It's a two-line fix to the fmalita@ change in flight, and this is a re-land, so
I'm going to hit Commit but note I am a big fan of fmalita@ improvement, and
supportive. Please make sure to fix PaintLayerCompositor.cpp:835 before landing
http://crrev.com/1849433002 presuming we go ahead with that.

If we decide it's reasonable to just remove GraphicsContext::FullyDisabled that
would be cool too. We're still in risky-land re: breaking Cluster Telemetry as
we've no tests in disabled context mode.

[wkorman, 2016-03-30 18:35:10]

The CQ bit was unchecked by wkorman@chromium.org

[wkorman, 2016-03-30 18:35:18]

Description was changed from

==========
Re-land: Make GraphicsLayer the DisplayItemClient for scrollbars composited via
PaintLayerCompositor.

Updated to deal gracefully with potentially null picture recording in
performance testing.

Original change description:

Currently, the DisplayItemClient is LayoutScrollbarPart. This has two
problems: the mapping between the LayoutScrollbarPart and its backing
is hard to reverse-engineer given the way the scrollbar code is set
up (LayoutScrollbarPart vs Scrollbar vs ScrollableArea), and the
fact that LayoutScrollbarPart can be painted in both non-composited
and composited modes. This distinction is important for computation
of correct visual rects.

This can be cleaned up by replaying the painted scrollbar content
with the GraphicsLayer backing as the DisplayItemClient, which
has the correct visualRect() (i.e. bounds of GraphicsLayer).

BUG=529938

Committed: https://crrev.com/8460ef8fc6125185abc1486eb61b0ca7fc9298ad
Cr-Commit-Position: refs/heads/master@{#382778}

patch from issue 1825193002 at patchset 100001
(http://crrev.com/1825193002#ps100001)
==========

to

==========
Re-land: Make GraphicsLayer the DisplayItemClient for scrollbars composited via
PaintLayerCompositor.

Updated to deal gracefully with potentially null picture recording in
performance testing.

Original change description:

Currently, the DisplayItemClient is LayoutScrollbarPart. This has two
problems: the mapping between the LayoutScrollbarPart and its backing
is hard to reverse-engineer given the way the scrollbar code is set
up (LayoutScrollbarPart vs Scrollbar vs ScrollableArea), and the
fact that LayoutScrollbarPart can be painted in both non-composited
and composited modes. This distinction is important for computation
of correct visual rects.

This can be cleaned up by replaying the painted scrollbar content
with the GraphicsLayer backing as the DisplayItemClient, which
has the correct visualRect() (i.e. bounds of GraphicsLayer).

BUG=529938

Committed: https://crrev.com/8460ef8fc6125185abc1486eb61b0ca7fc9298ad
Cr-Commit-Position: refs/heads/master@{#382778}

patch from issue 1825193002 at patchset 100001
(http://crrev.com/1825193002#ps100001)

TBR=chrishtr
==========

[wkorman, 2016-03-30 18:35:23]

The CQ bit was checked by wkorman@chromium.org

[commit-bot: I haz the power, 2016-03-30 18:36:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1844993002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1844993002/1

[f(malita), 2016-03-30 18:37:49]

lgtm

[commit-bot: I haz the power, 2016-03-30 20:09:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-30 20:11:15]

Description was changed from

==========
Re-land: Make GraphicsLayer the DisplayItemClient for scrollbars composited via
PaintLayerCompositor.

Updated to deal gracefully with potentially null picture recording in
performance testing.

Original change description:

Currently, the DisplayItemClient is LayoutScrollbarPart. This has two
problems: the mapping between the LayoutScrollbarPart and its backing
is hard to reverse-engineer given the way the scrollbar code is set
up (LayoutScrollbarPart vs Scrollbar vs ScrollableArea), and the
fact that LayoutScrollbarPart can be painted in both non-composited
and composited modes. This distinction is important for computation
of correct visual rects.

This can be cleaned up by replaying the painted scrollbar content
with the GraphicsLayer backing as the DisplayItemClient, which
has the correct visualRect() (i.e. bounds of GraphicsLayer).

BUG=529938

Committed: https://crrev.com/8460ef8fc6125185abc1486eb61b0ca7fc9298ad
Cr-Commit-Position: refs/heads/master@{#382778}

patch from issue 1825193002 at patchset 100001
(http://crrev.com/1825193002#ps100001)

TBR=chrishtr
==========

to

==========
Re-land: Make GraphicsLayer the DisplayItemClient for scrollbars composited via
PaintLayerCompositor.

Updated to deal gracefully with potentially null picture recording in
performance testing.

Original change description:

Currently, the DisplayItemClient is LayoutScrollbarPart. This has two
problems: the mapping between the LayoutScrollbarPart and its backing
is hard to reverse-engineer given the way the scrollbar code is set
up (LayoutScrollbarPart vs Scrollbar vs ScrollableArea), and the
fact that LayoutScrollbarPart can be painted in both non-composited
and composited modes. This distinction is important for computation
of correct visual rects.

This can be cleaned up by replaying the painted scrollbar content
with the GraphicsLayer backing as the DisplayItemClient, which
has the correct visualRect() (i.e. bounds of GraphicsLayer).

BUG=529938

Committed: https://crrev.com/8460ef8fc6125185abc1486eb61b0ca7fc9298ad
Cr-Commit-Position: refs/heads/master@{#382778}

patch from issue 1825193002 at patchset 100001
(http://crrev.com/1825193002#ps100001)

TBR=chrishtr

Committed: https://crrev.com/7bd3f083b468f3ae88ac48ca9cdbaa918d148cbb
Cr-Commit-Position: refs/heads/master@{#384070}
==========

[commit-bot: I haz the power, 2016-03-30 20:11:17]

Patchset 1 (id:??) landed as
https://crrev.com/7bd3f083b468f3ae88ac48ca9cdbaa918d148cbb
Cr-Commit-Position: refs/heads/master@{#384070}