Invalidate whitespace text on text color changes

Invalidate whitespace text on text color changes

This patch updates the optimization added in [1] to invalidate
whitespace text on color changes because whitespace text can have
decorations such as underlines which still need to repaint.

The big idea of the optimization in [1] is to not unnecessarily repaint
expensive items such as images that are in an <a> element. On hover, <a>
will change color and underline styles which should not affect images.
This patch adds a test to prove this optimization still works and
prevents it from breaking in the future.

[1] https://src.chromium.org/viewvc/blink?view=rev&revision=152046

BUG=529944
Committed: https://crrev.com/865c4bd7edd70fad53c2ae48b754ec8fca6f5e60
git-svn-id: svn://svn.chromium.org/blink/trunk@202164 bbb929c8-8fbe-4397-9dbb-9b2b20218538

[pdr., 2015-09-11 05:48:26]

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

[commit-bot: I haz the power, 2015-09-11 05:48:38]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1332233002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1332233002/1

[commit-bot: I haz the power, 2015-09-11 06:39:54]

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

[commit-bot: I haz the power, 2015-09-11 06:39:55]

Dry run: Try jobs failed on following builders:
  win_chromium_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[pdr., 2015-09-11 06:50:21]

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

[chrishtr, 2015-09-11 16:49:19]

https://codereview.chromium.org/1332233002/diff/1/Source/core/layout/LayoutOb...
File Source/core/layout/LayoutObject.cpp (right):

https://codereview.chromium.org/1332233002/diff/1/Source/core/layout/LayoutOb...
Source/core/layout/LayoutObject.cpp:1737: if (isText() || style()->hasBorder()
|| style()->hasOutline() || style()->isBackgroundColorCurrentColor())
Add a comment about why we're whitelisting only certain types of element.

[pdr., 2015-09-11 19:50:42]

On 2015/09/11 at 16:49:19, chrishtr wrote:
>
https://codereview.chromium.org/1332233002/diff/1/Source/core/layout/LayoutOb...
> File Source/core/layout/LayoutObject.cpp (right):
> 
>
https://codereview.chromium.org/1332233002/diff/1/Source/core/layout/LayoutOb...
> Source/core/layout/LayoutObject.cpp:1737: if (isText() || style()->hasBorder()
|| style()->hasOutline() || style()->isBackgroundColorCurrentColor())
> Add a comment about why we're whitelisting only certain types of element.

I think this may have been confusing because I reformatted the lines. I've
reverted this back to look more like the original code in the latest patch, and
updated it to skip <br> nodes.

PTAL

[pdr., 2015-09-11 19:50:49]

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

[commit-bot: I haz the power, 2015-09-11 19:50:59]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1332233002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1332233002/20001

[chrishtr, 2015-09-11 19:54:49]

https://codereview.chromium.org/1332233002/diff/20001/Source/core/layout/Layo...
File Source/core/layout/LayoutObject.cpp (right):

https://codereview.chromium.org/1332233002/diff/20001/Source/core/layout/Layo...
Source/core/layout/LayoutObject.cpp:1736: if (diff.textOrColorChanged() &&
!diff.needsPaintInvalidation()) {
Let's change to textDecorationOrColorChanged().

[pdr., 2015-09-11 19:58:40]

On 2015/09/11 at 19:54:49, chrishtr wrote:
>
https://codereview.chromium.org/1332233002/diff/20001/Source/core/layout/Layo...
> File Source/core/layout/LayoutObject.cpp (right):
> 
>
https://codereview.chromium.org/1332233002/diff/20001/Source/core/layout/Layo...
> Source/core/layout/LayoutObject.cpp:1736: if (diff.textOrColorChanged() &&
!diff.needsPaintInvalidation()) {
> Let's change to textDecorationOrColorChanged().

SGTM

Done.

[pdr., 2015-09-11 19:58:44]

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

[commit-bot: I haz the power, 2015-09-11 19:58:56]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1332233002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1332233002/40001

[chrishtr, 2015-09-11 19:59:24]

lgtm

[commit-bot: I haz the power, 2015-09-11 23:00:25]

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

[commit-bot: I haz the power, 2015-09-11 23:00:26]

Dry run: This issue passed the CQ dry run.

[pdr., 2015-09-11 23:01:28]

The CQ bit was checked by pdr@chromium.org

[commit-bot: I haz the power, 2015-09-11 23:01:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1332233002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1332233002/40001

[commit-bot: I haz the power, 2015-09-11 23:10:13]

Committed patchset #3 (id:40001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=202164

[pdr., 2015-09-15 19:54:26]

A revert of this CL (patchset #3 id:40001) has been created in
https://codereview.chromium.org/1345833003/ by pdr@chromium.org.

The reason for reverting is: Caused a perf regression on
https://chromeperf.appspot.com/report?sid=853c237ff4d1aba523371425b1de88bf28b....

[commit-bot: I haz the power, 2015-09-23 12:27:04]

Patchset 3 (id:??) landed as
https://crrev.com/865c4bd7edd70fad53c2ae48b754ec8fca6f5e60