Add Layout Test to test if skew is applied on both axes together not sequentially on Compositor

Apply skew on both axes together rather than sequentially on Compositor thread

This is the Layout Test that refers to crrev.com/1325803002. This 
patch applies skew on both axes together rather than calling 
skewX(angle_x) and skewX(angle_Y) sequentially.

BUG=268468
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=201704

[nainar1, 2015-09-02 07:14:56]

nainar@google.com changed reviewers:
+ ajuma@chromium.org, alancutter@chromium.org, timloh@chromium.org

[nainar1, 2015-09-02 07:14:56]

Hi,

This is the Layout Test in relation to crrev.com/1325803002. 

Please take a look?

Thanks!

[alancutter (OOO until 2018), 2015-09-03 01:15:34]

This test/patch doesn't need to address the compositor specifically, it can test
both main thread and compositor thread animation. I recommend putting the test
in LayoutTests/animations.

You shouldn't add -expected.txt or -expected.png files if possible, instead use
-expected.html.

https://codereview.chromium.org/1315973003/diff/40001/LayoutTests/compositing...
File LayoutTests/compositing/transitions/skew-notsequential-compositor.html
(right):

https://codereview.chromium.org/1315973003/diff/40001/LayoutTests/compositing...
LayoutTests/compositing/transitions/skew-notsequential-compositor.html:24:
<div></div>
For test readability you should have a red expected div and a green test div
that completely obscures the expectation when correct.

[nainar1, 2015-09-03 04:07:30]

Hi all,

I have rewritten the test and moved it to ManualTest since the test seems to be
rendering differently on the compositor thread. Could you all please take a
look?

Thanks!

https://codereview.chromium.org/1315973003/diff/40001/LayoutTests/compositing...
File LayoutTests/compositing/transitions/skew-notsequential-compositor.html
(right):

https://codereview.chromium.org/1315973003/diff/40001/LayoutTests/compositing...
LayoutTests/compositing/transitions/skew-notsequential-compositor.html:24:
<div></div>
Done.

[alancutter (OOO until 2018), 2015-09-03 04:25:14]

https://codereview.chromium.org/1315973003/diff/60001/ManualTests/animation/s...
File ManualTests/animation/skew-notsequential-compositor.html (right):

https://codereview.chromium.org/1315973003/diff/60001/ManualTests/animation/s...
ManualTests/animation/skew-notsequential-compositor.html:28: transform:
skew(-90deg, 90deg);
The from and to keyframes can both be skew(-45deg, 45deg).

https://codereview.chromium.org/1315973003/diff/60001/ManualTests/animation/s...
ManualTests/animation/skew-notsequential-compositor.html:34: transform:
skew(-45deg, 45deg);
Perhaps if the -expected.html was also running a composited animation it would
look the same. Try animating it with matrix(1, 1, 1, 1, 0, 0).

[nainar1, 2015-09-03 05:18:44]

Converted test from Manual to Layout test -> and have added the relevant
expectation images.

[alancutter (OOO until 2018), 2015-09-03 05:23:11]

lgtm with nit.

https://codereview.chromium.org/1315973003/diff/80001/LayoutTests/animations/...
File LayoutTests/animations/skew-notsequential-compositor.html (right):

https://codereview.chromium.org/1315973003/diff/80001/LayoutTests/animations/...
LayoutTests/animations/skew-notsequential-compositor.html:32: The green test div
should transform to cover the red target.
This text seems out of date as there's no red expectation div any more.

[nainar1, 2015-09-03 05:29:01]

The CQ bit was checked by nainar@google.com

[nainar1, 2015-09-03 05:29:02]

The patchset sent to the CQ was uploaded after l-g-t-m from
alancutter@chromium.org
Link to the patchset: https://codereview.chromium.org/1315973003/#ps100001
(title: "Remove outdated line")

[commit-bot: I haz the power, 2015-09-03 05:29:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1315973003/100001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1315973003/100001

[nainar1, 2015-09-03 06:00:19]

The CQ bit was unchecked by nainar@google.com

[nainar1, 2015-09-03 06:02:09]

The CQ bit was checked by nainar@google.com

[nainar1, 2015-09-03 06:02:09]

The patchset sent to the CQ was uploaded after l-g-t-m from
alancutter@chromium.org
Link to the patchset: https://codereview.chromium.org/1315973003/#ps120001
(title: "Add NeedsRebaseline for virtual/threaded test")

[commit-bot: I haz the power, 2015-09-03 06:02:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1315973003/120001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1315973003/120001

[commit-bot: I haz the power, 2015-09-03 06:51:46]

Committed patchset #7 (id:120001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=201704