cc: Fix occlusion tracking for layers with non-default blend modes

cc: Fix occlusion tracking for layers with non-default blend modes

When computing the occlusion from a layer, draw_blend_mode rather than
blend_mode needs to be considered, since draw_blend_mode is what's used
when drawing the layer. However, non-default blend modes currently always
trigger surface creation, and then the blend mode gets applied when
drawing the surface. This means that draw_blend_mode is always SrcOver.
This CL replaces the incorrect use of blend_mode in
OcclusionTracker::MarkOcclusionBehindLayer with a DCHECK that
draw_blend_mode is SrcOver.

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_blink_rel

Committed: https://crrev.com/2d466aa59bdd093b023b47ad861fbb0ddabce21f
Cr-Commit-Position: refs/heads/master@{#407572}

[ajuma, 2016-07-22 23:09:14]

Description was changed from

==========
cc: Fix occlusion tracking for layers with non-default blend modes
==========

to

==========
cc: Fix occlusion tracking for layers with non-default blend modes
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_blink_rel
==========

[ajuma, 2016-07-22 23:09:44]

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

[commit-bot: I haz the power, 2016-07-22 23:10:16]

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, 2016-07-23 00:11:18]

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

[commit-bot: I haz the power, 2016-07-23 00:11:18]

Dry run: This issue passed the CQ dry run.

[ajuma, 2016-07-25 18:26:11]

Description was changed from

==========
cc: Fix occlusion tracking for layers with non-default blend modes
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_blink_rel
==========

to

==========
cc: Fix occlusion tracking for layers with non-default blend modes

When computing the occlusion from a layer, draw_blend_mode rather than
blend_mode needs to be considered, since draw_blend_mode is what's used
when drawing the layer. However, non-default blend modes currently always
trigger surface creation, and then the blend modes get applied when
drawing the surface. This means that draw_blend_mode is always SrcOver.
This CL replaces the incorrect use of blend_mode in
OcclusionTracker::MarkOcclusionBehindLayer with a DCHECK that
draw_blend_mode is SrcOver.

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_blink_rel
==========

[ajuma, 2016-07-25 18:30:28]

Description was changed from

==========
cc: Fix occlusion tracking for layers with non-default blend modes

When computing the occlusion from a layer, draw_blend_mode rather than
blend_mode needs to be considered, since draw_blend_mode is what's used
when drawing the layer. However, non-default blend modes currently always
trigger surface creation, and then the blend modes get applied when
drawing the surface. This means that draw_blend_mode is always SrcOver.
This CL replaces the incorrect use of blend_mode in
OcclusionTracker::MarkOcclusionBehindLayer with a DCHECK that
draw_blend_mode is SrcOver.

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_blink_rel
==========

to

==========
cc: Fix occlusion tracking for layers with non-default blend modes

When computing the occlusion from a layer, draw_blend_mode rather than
blend_mode needs to be considered, since draw_blend_mode is what's used
when drawing the layer. However, non-default blend modes currently always
trigger surface creation, and then the blend modes get applied when
drawing the surface. This means that draw_blend_mode is always SrcOver.
This CL replaces the incorrect use of blend_mode in
OcclusionTracker::MarkOcclusionBehindLayer with a DCHECK that
draw_blend_mode is SrcOver.

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_blink_rel
==========

[ajuma, 2016-07-25 18:30:28]

ajuma@chromium.org changed reviewers:
+ enne@chromium.org

[ajuma, 2016-07-25 18:34:21]

Description was changed from

==========
cc: Fix occlusion tracking for layers with non-default blend modes

When computing the occlusion from a layer, draw_blend_mode rather than
blend_mode needs to be considered, since draw_blend_mode is what's used
when drawing the layer. However, non-default blend modes currently always
trigger surface creation, and then the blend modes get applied when
drawing the surface. This means that draw_blend_mode is always SrcOver.
This CL replaces the incorrect use of blend_mode in
OcclusionTracker::MarkOcclusionBehindLayer with a DCHECK that
draw_blend_mode is SrcOver.

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_blink_rel
==========

to

==========
cc: Fix occlusion tracking for layers with non-default blend modes

When computing the occlusion from a layer, draw_blend_mode rather than
blend_mode needs to be considered, since draw_blend_mode is what's used
when drawing the layer. However, non-default blend modes currently always
trigger surface creation, and then the blend mode gets applied when
drawing the surface. This means that draw_blend_mode is always SrcOver.
This CL replaces the incorrect use of blend_mode in
OcclusionTracker::MarkOcclusionBehindLayer with a DCHECK that
draw_blend_mode is SrcOver.

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_blink_rel
==========

[ajuma, 2016-07-25 18:34:42]

https://codereview.chromium.org/2176903002/diff/1/cc/trees/occlusion_tracker.cc
File cc/trees/occlusion_tracker.cc (right):

https://codereview.chromium.org/2176903002/diff/1/cc/trees/occlusion_tracker....
cc/trees/occlusion_tracker.cc:355: DCHECK_EQ(layer->draw_blend_mode(),
SkXfermode::kSrcOver_Mode);
An alternative would be to delete draw_blend_mode for now. There's an open bug
for not always creating surfaces for blend mode (http://crbug.com/301738) but
it's been open for a while and is currently unowned.

[enne (OOO), 2016-07-25 19:18:24]

lgtm

[ajuma, 2016-07-25 19:45:33]

The CQ bit was checked by ajuma@chromium.org

[commit-bot: I haz the power, 2016-07-25 19:46:15]

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, 2016-07-25 21:14:36]

Description was changed from

==========
cc: Fix occlusion tracking for layers with non-default blend modes

When computing the occlusion from a layer, draw_blend_mode rather than
blend_mode needs to be considered, since draw_blend_mode is what's used
when drawing the layer. However, non-default blend modes currently always
trigger surface creation, and then the blend mode gets applied when
drawing the surface. This means that draw_blend_mode is always SrcOver.
This CL replaces the incorrect use of blend_mode in
OcclusionTracker::MarkOcclusionBehindLayer with a DCHECK that
draw_blend_mode is SrcOver.

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_blink_rel
==========

to

==========
cc: Fix occlusion tracking for layers with non-default blend modes

When computing the occlusion from a layer, draw_blend_mode rather than
blend_mode needs to be considered, since draw_blend_mode is what's used
when drawing the layer. However, non-default blend modes currently always
trigger surface creation, and then the blend mode gets applied when
drawing the surface. This means that draw_blend_mode is always SrcOver.
This CL replaces the incorrect use of blend_mode in
OcclusionTracker::MarkOcclusionBehindLayer with a DCHECK that
draw_blend_mode is SrcOver.

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_blink_rel
==========

[commit-bot: I haz the power, 2016-07-25 21:14:37]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-07-25 21:17:21]

Description was changed from

==========
cc: Fix occlusion tracking for layers with non-default blend modes

When computing the occlusion from a layer, draw_blend_mode rather than
blend_mode needs to be considered, since draw_blend_mode is what's used
when drawing the layer. However, non-default blend modes currently always
trigger surface creation, and then the blend mode gets applied when
drawing the surface. This means that draw_blend_mode is always SrcOver.
This CL replaces the incorrect use of blend_mode in
OcclusionTracker::MarkOcclusionBehindLayer with a DCHECK that
draw_blend_mode is SrcOver.

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_blink_rel
==========

to

==========
cc: Fix occlusion tracking for layers with non-default blend modes

When computing the occlusion from a layer, draw_blend_mode rather than
blend_mode needs to be considered, since draw_blend_mode is what's used
when drawing the layer. However, non-default blend modes currently always
trigger surface creation, and then the blend mode gets applied when
drawing the surface. This means that draw_blend_mode is always SrcOver.
This CL replaces the incorrect use of blend_mode in
OcclusionTracker::MarkOcclusionBehindLayer with a DCHECK that
draw_blend_mode is SrcOver.

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_blink_rel

Committed: https://crrev.com/2d466aa59bdd093b023b47ad861fbb0ddabce21f
Cr-Commit-Position: refs/heads/master@{#407572}
==========

[commit-bot: I haz the power, 2016-07-25 21:17:22]

Patchset 1 (id:??) landed as
https://crrev.com/2d466aa59bdd093b023b47ad861fbb0ddabce21f
Cr-Commit-Position: refs/heads/master@{#407572}