Only automatically promote scrollers which are untransformed and opaque.

Only automatically promote scrollers which are untransformed and opaque.

To be sure that we actually get LCD text, we only promote scrollers which have
not been transformed themselves or by any ancestor, and also exclude those
which are translucent due to an opacity on themselves or an ancestor.

BUG=644833
TEST=PaintLayerScrollableAreaTest.OnlyNonTransformedOpaqueLayersPromoted, PaintLayerScrollableAreaTest.OnlyOpaqueLayersPromoted
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/c656b155c2f6fb63288a259d130dd06dca393925
Cr-Commit-Position: refs/heads/master@{#426385}

[flackr, 2016-10-19 22:03:53]

Description was changed from

==========
Only automatically promote scrollers which are untransformed and opaque.

To be sure that we actually get LCD text, we only promote scrollers which have
not been transformed themselves or by any ancestor, and also exclude those
which are translucent due to an opacity on themselves or an ancestor.

BUG=644833
TEST=PaintLayerScrollableAreaTest.OnlyNonTransformedOpaqueLayersPromoted,
PaintLayerScrollableAreaTest.OnlyOpaqueLayersPromoted
==========

to

==========
Only automatically promote scrollers which are untransformed and opaque.

To be sure that we actually get LCD text, we only promote scrollers which have
not been transformed themselves or by any ancestor, and also exclude those
which are translucent due to an opacity on themselves or an ancestor.

BUG=644833
TEST=PaintLayerScrollableAreaTest.OnlyNonTransformedOpaqueLayersPromoted,
PaintLayerScrollableAreaTest.OnlyOpaqueLayersPromoted
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[flackr, 2016-10-19 22:09:18]

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

[flackr, 2016-10-19 22:09:19]

Chris,

I investigated allowing integer transforms, but it's going to be trickier than I
thought to make the fast transform update path work with this since it only
forces promotion when there is potential overlap. For now, let's go with your
original suggestion to not allow any transforms and I can look into adding
integer translation support later.

WDYT? Thanks,
Rob

P.S. schenney@ Fixing this ended up being a pretty simple patch since we already
track ancestor transform and opacity parents, i.e. we could merge this back to
M55 if we want to keep opaque scrolling on and not need to turn off the trial.

[chrishtr, 2016-10-19 22:29:45]

The CQ bit was checked by chrishtr@chromium.org

[chrishtr, 2016-10-19 22:29:45]

lgtm

https://chromiumcodereview.appspot.com/2434443005/diff/1/third_party/WebKit/S...
File third_party/WebKit/Source/core/paint/PaintLayerScrollableAreaTest.cpp
(right):

https://chromiumcodereview.appspot.com/2434443005/diff/1/third_party/WebKit/S...
third_party/WebKit/Source/core/paint/PaintLayerScrollableAreaTest.cpp:246:
RuntimeEnabledFeatures::setCompositeOpaqueScrollersEnabled(true);
Use the auto-resetter pattern.

[commit-bot: I haz the power, 2016-10-19 22:30:45]

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

[flackr, 2016-10-19 23:00:15]

The CQ bit was unchecked by flackr@chromium.org

[flackr, 2016-10-19 23:01:44]

The CQ bit was checked by flackr@chromium.org

[flackr, 2016-10-19 23:01:49]

The patchset sent to the CQ was uploaded after l-g-t-m from
chrishtr@chromium.org
Link to the patchset: https://chromiumcodereview.appspot.com/2434443005/#ps20001
(title: "Use ScopedRuntimeEnabledFeatureForTest pattern.")

[flackr, 2016-10-19 23:01:55]

https://chromiumcodereview.appspot.com/2434443005/diff/1/third_party/WebKit/S...
File third_party/WebKit/Source/core/paint/PaintLayerScrollableAreaTest.cpp
(right):

https://chromiumcodereview.appspot.com/2434443005/diff/1/third_party/WebKit/S...
third_party/WebKit/Source/core/paint/PaintLayerScrollableAreaTest.cpp:246:
RuntimeEnabledFeatures::setCompositeOpaqueScrollersEnabled(true);
On 2016/10/19 at 22:29:45, chrishtr wrote:
> Use the auto-resetter pattern.

Done.

[commit-bot: I haz the power, 2016-10-19 23:02:59]

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, 2016-10-20 00:43:17]

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

[commit-bot: I haz the power, 2016-10-20 00:43:18]

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, 2016-10-20 01:06:03]

The CQ bit was checked by flackr@chromium.org

[flackr, 2016-10-20 01:06:04]

The patchset sent to the CQ was uploaded after l-g-t-m from
chrishtr@chromium.org
Link to the patchset: https://codereview.chromium.org/2434443005/#ps40001
(title: "Force compositing to test scrolling contents background painting")

[commit-bot: I haz the power, 2016-10-20 01:06:36]

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, 2016-10-20 03:30:32]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-10-21 13:14:54]

Description was changed from

==========
Only automatically promote scrollers which are untransformed and opaque.

To be sure that we actually get LCD text, we only promote scrollers which have
not been transformed themselves or by any ancestor, and also exclude those
which are translucent due to an opacity on themselves or an ancestor.

BUG=644833
TEST=PaintLayerScrollableAreaTest.OnlyNonTransformedOpaqueLayersPromoted,
PaintLayerScrollableAreaTest.OnlyOpaqueLayersPromoted
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Only automatically promote scrollers which are untransformed and opaque.

To be sure that we actually get LCD text, we only promote scrollers which have
not been transformed themselves or by any ancestor, and also exclude those
which are translucent due to an opacity on themselves or an ancestor.

BUG=644833
TEST=PaintLayerScrollableAreaTest.OnlyNonTransformedOpaqueLayersPromoted,
PaintLayerScrollableAreaTest.OnlyOpaqueLayersPromoted
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/c656b155c2f6fb63288a259d130dd06dca393925
Cr-Commit-Position: refs/heads/master@{#426385}
==========

[commit-bot: I haz the power, 2016-10-21 13:14:55]

Patchset 3 (id:??) landed as
https://crrev.com/c656b155c2f6fb63288a259d130dd06dca393925
Cr-Commit-Position: refs/heads/master@{#426385}