Disable subsequence caching for spv2

Disable subsequence caching for spv2

Invalidation does not currently work properly in spv2 and subsequence
caching would cause subtrees to incorrectly paint when spv2 was enabled.
On real websites this results in flashing content that should have
painted but didn't, or flashes of cached content incorrectly drawn at
the origin.

This patch disables subsequence caching which fixes google.com and
several layout tests.

BUG=596780
Committed: https://crrev.com/bfb0fc4dbd0648aac537ca64ad6fffad621eb6be
Cr-Commit-Position: refs/heads/master@{#382675}

[pdr., 2016-03-22 06:12:37]

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

[commit-bot: I haz the power, 2016-03-22 06:12:49]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1820793004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1820793004/1

[pdr., 2016-03-22 06:13:10]

pdr@chromium.org changed reviewers:
+ wangxianzhu@chromium.org

[commit-bot: I haz the power, 2016-03-22 08:33:25]

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

[commit-bot: I haz the power, 2016-03-22 08:33:26]

Dry run: This issue passed the CQ dry run.

[Xianzhu, 2016-03-22 16:35:11]

lgtm

https://codereview.chromium.org/1820793004/diff/1/third_party/WebKit/Source/p...
File third_party/WebKit/Source/platform/graphics/paint/SubsequenceRecorder.cpp
(right):

https://codereview.chromium.org/1820793004/diff/1/third_party/WebKit/Source/p...
third_party/WebKit/Source/platform/graphics/paint/SubsequenceRecorder.cpp:22: 
Nit: TODO(<wangxianzhu or pdr>): Make it work.

and would you assign the bug to me?

[Xianzhu, 2016-03-22 17:03:31]

https://codereview.chromium.org/1820793004/diff/1/third_party/WebKit/Source/p...
File third_party/WebKit/Source/platform/graphics/paint/SubsequenceRecorder.cpp
(right):

https://codereview.chromium.org/1820793004/diff/1/third_party/WebKit/Source/p...
third_party/WebKit/Source/platform/graphics/paint/SubsequenceRecorder.cpp:22: 
On 2016/03/22 16:35:11, Xianzhu wrote:
> Nit: TODO(<wangxianzhu or pdr>): Make it work.
> 
> and would you assign the bug to me?

Fwiw, just found that there is a TODO(<bug>) style.

[pdr., 2016-03-22 19:05:36]

Description was changed from

==========
Disable subsequence caching for spv2

Invalidation does not currently work properly in spv2 and subsequence
caching would cause subtrees to incorrectly paint when spv2 was enabled.
On real websites this results in flashing content that should have
painted but didn't, or flashes of cached content incorrectly drawn at
the origin.

This patch disables subsequence caching which fixes google.com and
several layout tests (most new passing tests are masked by paint
invalidation text differences which will be addressed in a followup).

BUG=596780
==========

to

==========
Disable subsequence caching for spv2

Invalidation does not currently work properly in spv2 and subsequence
caching would cause subtrees to incorrectly paint when spv2 was enabled.
On real websites this results in flashing content that should have
painted but didn't, or flashes of cached content incorrectly drawn at
the origin.

This patch disables subsequence caching which fixes google.com and
several layout tests.

BUG=596780
==========

[pdr., 2016-03-22 19:16:29]

The CQ bit was checked by pdr@chromium.org

[pdr., 2016-03-22 19:16:29]

Thanks!

I updated TestExpectations in the latest patch to have more explanations for the
failures too.

https://codereview.chromium.org/1820793004/diff/1/third_party/WebKit/Source/p...
File third_party/WebKit/Source/platform/graphics/paint/SubsequenceRecorder.cpp
(right):

https://codereview.chromium.org/1820793004/diff/1/third_party/WebKit/Source/p...
third_party/WebKit/Source/platform/graphics/paint/SubsequenceRecorder.cpp:22: 
On 2016/03/22 at 17:03:30, Xianzhu wrote:
> On 2016/03/22 16:35:11, Xianzhu wrote:
> > Nit: TODO(<wangxianzhu or pdr>): Make it work.
> > 
> > and would you assign the bug to me?
> 
> Fwiw, just found that there is a TODO(<bug>) style.

Done!

I filed this as https://crbug.com/596983, but please hold off on implementing it
for a while.

For the comment style, I also prefer bug #'s but others don't agree with us :)
The most recent discussion I could find was in
https://groups.google.com/a/chromium.org/d/msg/blink-dev/fS6tZ-qNx9I/agpjaazf...
where it sounds like "TODO(pdr): blah blah crbug.com/1234" is the preferred
approach for now.

[pdr., 2016-03-22 19:16:30]

The patchset sent to the CQ was uploaded after l-g-t-m from
wangxianzhu@chromium.org
Link to the patchset: https://codereview.chromium.org/1820793004/#ps20001
(title: "Add todo, and add more complete entries to TestExpectations")

[commit-bot: I haz the power, 2016-03-22 19:17:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1820793004/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1820793004/20001

[commit-bot: I haz the power, 2016-03-22 20:55:13]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-03-22 20:56:49]

Description was changed from

==========
Disable subsequence caching for spv2

Invalidation does not currently work properly in spv2 and subsequence
caching would cause subtrees to incorrectly paint when spv2 was enabled.
On real websites this results in flashing content that should have
painted but didn't, or flashes of cached content incorrectly drawn at
the origin.

This patch disables subsequence caching which fixes google.com and
several layout tests.

BUG=596780
==========

to

==========
Disable subsequence caching for spv2

Invalidation does not currently work properly in spv2 and subsequence
caching would cause subtrees to incorrectly paint when spv2 was enabled.
On real websites this results in flashing content that should have
painted but didn't, or flashes of cached content incorrectly drawn at
the origin.

This patch disables subsequence caching which fixes google.com and
several layout tests.

BUG=596780

Committed: https://crrev.com/bfb0fc4dbd0648aac537ca64ad6fffad621eb6be
Cr-Commit-Position: refs/heads/master@{#382675}
==========

[commit-bot: I haz the power, 2016-03-22 20:56:50]

Patchset 2 (id:??) landed as
https://crrev.com/bfb0fc4dbd0648aac537ca64ad6fffad621eb6be
Cr-Commit-Position: refs/heads/master@{#382675}