Only promote opaque scrollers which are stacking contexts.

Only promote opaque scrollers which are stacking contexts.

Promoting a scroller which is not a stacking context means that any positioned
descendant must be promoted which will lose LCD text unless it is also opaque.

BUG=666147
TEST=PaintLayerScrollableAreaTest.NonContainedLayersNotPromoted
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/9a94cf9be5c058b5007811e9c42aabed46a5d944
Cr-Commit-Position: refs/heads/master@{#433578}

[flackr, 2016-11-17 02:12:42]

Description was changed from

==========
Only promote opaque scrollers which are stacking contexts.

Promoting a scroller which is not a stacking context means that any positioned
descendant must be promoted which will lose LCD text unless it is also opaque.

BUG=666147
==========

to

==========
Only promote opaque scrollers which are stacking contexts.

Promoting a scroller which is not a stacking context means that any positioned
descendant must be promoted which will lose LCD text unless it is also opaque.

BUG=666147
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[flackr, 2016-11-17 02:13:04]

The CQ bit was checked by flackr@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-17 02:13:50]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-17 04:03:39]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-17 04:03:40]

Dry run: Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[flackr, 2016-11-17 15:58:45]

Description was changed from

==========
Only promote opaque scrollers which are stacking contexts.

Promoting a scroller which is not a stacking context means that any positioned
descendant must be promoted which will lose LCD text unless it is also opaque.

BUG=666147
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Only promote opaque scrollers which are stacking contexts.

Promoting a scroller which is not a stacking context means that any positioned
descendant must be promoted which will lose LCD text unless it is also opaque.

BUG=666147
TEST=PaintLayerScrollableAreaTest.NonContainedLayersNotPromoted
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[flackr, 2016-11-17 15:58:46]

flackr@chromium.org changed reviewers:
+ schenney@chromium.org

[flackr, 2016-11-17 16:02:17]

Hey, I discovered this problem while fixing the custom scrollbar compositing
issue for gmail. Unfortunately, even with my fix gmail still cannot be
composited because within the scroller there is a positioned element. Since the
scroller doesn't contain it, it is promoted into a separate layer which is not
opaque and so loses LCD text.

This patch makes sure we don't promote in this case where we may lose LCD text,
I'll look into following this up with some detection of non-opaque positioned
descendants.

Please take a look, thanks.

[Stephen Chennney, 2016-11-17 16:37:44]

lgtm. Thanks for all your work on this.

[flackr, 2016-11-17 16:57:21]

The CQ bit was checked by flackr@chromium.org

[commit-bot: I haz the power, 2016-11-17 16:57:48]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[chrishtr, 2016-11-17 17:41:21]

chrishtr@chromium.org changed reviewers:
+ chrishtr@chromium.org

[chrishtr, 2016-11-17 17:41:21]

It's time to ask gmail to make their scroller a stacking context. I don't recall
if we
ever tried very hard to ask them for that.

[commit-bot: I haz the power, 2016-11-17 18:21:36]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-17 18:21:38]

Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[flackr, 2016-11-17 19:45:56]

The CQ bit was checked by flackr@chromium.org

[commit-bot: I haz the power, 2016-11-17 19:46:49]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-17 19:53:46]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-17 19:53:48]

Try jobs failed on following builders:
  linux_layout_tests_slimming_paint_v2 on master.tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)

[flackr, 2016-11-18 00:15:12]

The CQ bit was checked by flackr@chromium.org

[flackr, 2016-11-18 00:15:13]

The patchset sent to the CQ was uploaded after l-g-t-m from
schenney@chromium.org
Link to the patchset: https://codereview.chromium.org/2509203002/#ps40001
(title: "Test rebaselines.")

[commit-bot: I haz the power, 2016-11-18 00:16:51]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-18 02:00:20]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-18 02:00:21]

Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[flackr, 2016-11-18 03:39:43]

The CQ bit was checked by flackr@chromium.org

[flackr, 2016-11-18 03:39:44]

The patchset sent to the CQ was uploaded after l-g-t-m from
schenney@chromium.org
Link to the patchset: https://codereview.chromium.org/2509203002/#ps80001
(title: "Restore master android baselines.")

[commit-bot: I haz the power, 2016-11-18 03:41:25]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-18 05:42:57]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-18 05:42:59]

Try jobs failed on following builders:
  linux_layout_tests_slimming_paint_v2 on master.tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)

[flackr, 2016-11-18 14:57:23]

The CQ bit was checked by flackr@chromium.org

[commit-bot: I haz the power, 2016-11-18 14:57:56]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-18 15:30:17]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-18 15:30:18]

Try jobs failed on following builders:
  linux_layout_tests_slimming_paint_v2 on master.tryserver.chromium.linux
(JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_layout_te...)

[flackr, 2016-11-18 20:01:59]

Patchset #6 (id:100001) has been deleted

[flackr, 2016-11-18 20:10:55]

The CQ bit was checked by flackr@chromium.org

[flackr, 2016-11-18 20:10:56]

The patchset sent to the CQ was uploaded after l-g-t-m from
schenney@chromium.org
Link to the patchset: https://codereview.chromium.org/2509203002/#ps120001
(title: "Add expected failures on slimming paint tests.")

[commit-bot: I haz the power, 2016-11-18 20:11:35]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[pdr., 2016-11-18 20:36:54]

On 2016/11/18 at 20:11:35, commit-bot wrote:
> CQ is trying da patch. Follow status at
>  
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

FlagExpectations/enable-slimming-paint-v2 lgtm. Rob and I talked offline: these
are just cases where the layerization decisions differ between spv1 and spv2.
Hope to clean that up soon.

[commit-bot: I haz the power, 2016-11-18 22:11:46]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-18 22:11:48]

Try jobs failed on following builders:
  linux_chromium_asan_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  win_chromium_rel_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[flackr, 2016-11-19 15:38:00]

The CQ bit was checked by flackr@chromium.org

[flackr, 2016-11-19 15:38:01]

The patchset sent to the CQ was uploaded after l-g-t-m from
schenney@chromium.org, pdr@chromium.org
Link to the patchset: https://codereview.chromium.org/2509203002/#ps130001
(title: "Add contain paint to composited scrolling test.")

[commit-bot: I haz the power, 2016-11-19 15:38:10]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-19 15:41:20]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-19 15:41:22]

Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[flackr, 2016-11-20 18:18:34]

The CQ bit was checked by flackr@chromium.org

[flackr, 2016-11-20 18:18:34]

The patchset sent to the CQ was uploaded after l-g-t-m from
schenney@chromium.org, pdr@chromium.org
Link to the patchset: https://codereview.chromium.org/2509203002/#ps150001
(title: "Merge with master.")

[commit-bot: I haz the power, 2016-11-20 18:18:43]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-20 20:01:24]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-11-20 20:01:25]

Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[flackr, 2016-11-21 16:08:11]

The CQ bit was checked by flackr@chromium.org

[flackr, 2016-11-21 16:08:12]

The patchset sent to the CQ was uploaded after l-g-t-m from
schenney@chromium.org, pdr@chromium.org
Link to the patchset: https://codereview.chromium.org/2509203002/#ps170001
(title: "Add contain paint to local equivalent background invalidation test.")

[commit-bot: I haz the power, 2016-11-21 16:08:47]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-21 17:38:41]

CQ is committing da patch.

Bot data: {"patchset_id": 170001, "attempt_start_ts": 1479744491688810,
"parent_rev": "3f9887b0d484f9daa5e7dd6541490dd7f6323fa6", "commit_rev":
"ee9b9f18aa3b53fe93c086d3c4e3f730f417dc57"}

[commit-bot: I haz the power, 2016-11-21 17:39:15]

Committed patchset #9 (id:170001)

[commit-bot: I haz the power, 2016-11-21 17:42:29]

Description was changed from

==========
Only promote opaque scrollers which are stacking contexts.

Promoting a scroller which is not a stacking context means that any positioned
descendant must be promoted which will lose LCD text unless it is also opaque.

BUG=666147
TEST=PaintLayerScrollableAreaTest.NonContainedLayersNotPromoted
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Only promote opaque scrollers which are stacking contexts.

Promoting a scroller which is not a stacking context means that any positioned
descendant must be promoted which will lose LCD text unless it is also opaque.

BUG=666147
TEST=PaintLayerScrollableAreaTest.NonContainedLayersNotPromoted
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/9a94cf9be5c058b5007811e9c42aabed46a5d944
Cr-Commit-Position: refs/heads/master@{#433578}
==========

[commit-bot: I haz the power, 2016-11-21 17:42:32]

Patchset 9 (id:??) landed as
https://crrev.com/9a94cf9be5c058b5007811e9c42aabed46a5d944
Cr-Commit-Position: refs/heads/master@{#433578}

[mdjones, 2016-11-21 19:00:58]

A revert of this CL (patchset #9 id:170001) has been created in
https://codereview.chromium.org/2516303003/ by mdjones@chromium.org.

The reason for reverting is: Broke test:
svg/as-background-image/svg-width-100p-as-background.html.