Fix performance regression in WebGL to 2D canvas draws.

Fix performance regression in WebGL to 2D canvas draws.

Regression was introduced by this change:
https://codereview.chromium.org/2294383002

The change inadvertently modified the steps performed by
HTMLCanvasElement::getSourceImageForCanvas by no longer taking
advantage of the cached rendering results of the WebGL drawing buffer.
A secondary source of regression was that the AccelerationHint was
not being propagated correctly.

BUG=644401
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
TEST=blink_perf.canvas / draw-static-webgl-to-hw-accelerated-canvas-2d

Committed: https://crrev.com/980562f70d53ff313d4f5cd885c70248d3dd902a
Cr-Commit-Position: refs/heads/master@{#417029}

[Justin Novosad, 2016-09-07 14:48:14]

Description was changed from

==========
Fix performance regression in WebGL to 2D canvas draws.

Regression was introduced by this change:
https://codereview.chromium.org/2294383002

The change inadvertantly modified the steps performed by
HTMLCanvasElement::getSourceImageForCanvas by no longer taking
advantage of the cached rendering results of the WebGL drawing buffer.
A secondary source of regression was that the AccelerationHint was
not being propagated correctly.

BUG=644401
==========

to

==========
Fix performance regression in WebGL to 2D canvas draws.

Regression was introduced by this change:
https://codereview.chromium.org/2294383002

The change inadvertantly modified the steps performed by
HTMLCanvasElement::getSourceImageForCanvas by no longer taking
advantage of the cached rendering results of the WebGL drawing buffer.
A secondary source of regression was that the AccelerationHint was
not being propagated correctly.

BUG=644401
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
==========

[Justin Novosad, 2016-09-07 14:49:18]

junov@chromium.org changed reviewers:
+ kbr@chromium.org

[Justin Novosad, 2016-09-07 14:49:19]

@kbr: PTAL

[Justin Novosad, 2016-09-07 14:49:42]

Description was changed from

==========
Fix performance regression in WebGL to 2D canvas draws.

Regression was introduced by this change:
https://codereview.chromium.org/2294383002

The change inadvertantly modified the steps performed by
HTMLCanvasElement::getSourceImageForCanvas by no longer taking
advantage of the cached rendering results of the WebGL drawing buffer.
A secondary source of regression was that the AccelerationHint was
not being propagated correctly.

BUG=644401
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
==========

to

==========
Fix performance regression in WebGL to 2D canvas draws.

Regression was introduced by this change:
https://codereview.chromium.org/2294383002

The change inadvertently modified the steps performed by
HTMLCanvasElement::getSourceImageForCanvas by no longer taking
advantage of the cached rendering results of the WebGL drawing buffer.
A secondary source of regression was that the AccelerationHint was
not being propagated correctly.

BUG=644401
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
==========

[Justin Novosad, 2016-09-07 14:51:10]

Description was changed from

==========
Fix performance regression in WebGL to 2D canvas draws.

Regression was introduced by this change:
https://codereview.chromium.org/2294383002

The change inadvertently modified the steps performed by
HTMLCanvasElement::getSourceImageForCanvas by no longer taking
advantage of the cached rendering results of the WebGL drawing buffer.
A secondary source of regression was that the AccelerationHint was
not being propagated correctly.

BUG=644401
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
==========

to

==========
Fix performance regression in WebGL to 2D canvas draws.

Regression was introduced by this change:
https://codereview.chromium.org/2294383002

The change inadvertently modified the steps performed by
HTMLCanvasElement::getSourceImageForCanvas by no longer taking
advantage of the cached rendering results of the WebGL drawing buffer.
A secondary source of regression was that the AccelerationHint was
not being propagated correctly.

BUG=644401
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
TEST=blink_perf.canvas / draw-static-webgl-to-hw-accelerated-canvas-2d
==========

[Ken Russell (switch to Gerrit), 2016-09-07 17:49:31]

lgtm

Good to know there is a perf test covering this code path.

[Justin Novosad, 2016-09-07 18:08:22]

The CQ bit was checked by junov@chromium.org

[commit-bot: I haz the power, 2016-09-07 18:08:55]

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, 2016-09-07 19:35:37]

Description was changed from

==========
Fix performance regression in WebGL to 2D canvas draws.

Regression was introduced by this change:
https://codereview.chromium.org/2294383002

The change inadvertently modified the steps performed by
HTMLCanvasElement::getSourceImageForCanvas by no longer taking
advantage of the cached rendering results of the WebGL drawing buffer.
A secondary source of regression was that the AccelerationHint was
not being propagated correctly.

BUG=644401
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
TEST=blink_perf.canvas / draw-static-webgl-to-hw-accelerated-canvas-2d
==========

to

==========
Fix performance regression in WebGL to 2D canvas draws.

Regression was introduced by this change:
https://codereview.chromium.org/2294383002

The change inadvertently modified the steps performed by
HTMLCanvasElement::getSourceImageForCanvas by no longer taking
advantage of the cached rendering results of the WebGL drawing buffer.
A secondary source of regression was that the AccelerationHint was
not being propagated correctly.

BUG=644401
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
TEST=blink_perf.canvas / draw-static-webgl-to-hw-accelerated-canvas-2d
==========

[commit-bot: I haz the power, 2016-09-07 19:35:38]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-07 19:38:08]

Description was changed from

==========
Fix performance regression in WebGL to 2D canvas draws.

Regression was introduced by this change:
https://codereview.chromium.org/2294383002

The change inadvertently modified the steps performed by
HTMLCanvasElement::getSourceImageForCanvas by no longer taking
advantage of the cached rendering results of the WebGL drawing buffer.
A secondary source of regression was that the AccelerationHint was
not being propagated correctly.

BUG=644401
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
TEST=blink_perf.canvas / draw-static-webgl-to-hw-accelerated-canvas-2d
==========

to

==========
Fix performance regression in WebGL to 2D canvas draws.

Regression was introduced by this change:
https://codereview.chromium.org/2294383002

The change inadvertently modified the steps performed by
HTMLCanvasElement::getSourceImageForCanvas by no longer taking
advantage of the cached rendering results of the WebGL drawing buffer.
A secondary source of regression was that the AccelerationHint was
not being propagated correctly.

BUG=644401
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
TEST=blink_perf.canvas / draw-static-webgl-to-hw-accelerated-canvas-2d

Committed: https://crrev.com/980562f70d53ff313d4f5cd885c70248d3dd902a
Cr-Commit-Position: refs/heads/master@{#417029}
==========

[commit-bot: I haz the power, 2016-09-07 19:38:09]

Patchset 1 (id:??) landed as
https://crrev.com/980562f70d53ff313d4f5cd885c70248d3dd902a
Cr-Commit-Position: refs/heads/master@{#417029}