Store custom property backing strings in resolved CSSVariableData objects.

Store custom property backing strings in resolved CSSVariableData objects.

This is a defensive change - it seems unlikely that CSS Variables
can persist beyond the style sheets that create them, but it's also
easy and cheap to ensure that resolved CSS variables pin their
backing strings.

It's worth noting that resolved CSS Variables can *only* reference
either their own string, or strings from other *already resolved*
variables.

BUG=465126
Committed: https://crrev.com/e9e72810a4bd7900a69f86f40884ddb310189a92
Cr-Commit-Position: refs/heads/master@{#362913}

[shans, 2015-12-03 03:38:59]

shans@chromium.org changed reviewers:
+ timloh@chromium.org

[Timothy Loh, 2015-12-03 03:46:23]

On 2015/12/03 03:38:59, shans wrote:

lgtm, but BUG= should probably point to the custom properties metabug instead of
the cycle detection bug

[shans, 2015-12-03 03:55:45]

Description was changed from

==========
Store custom property backing strings in resolved CSSVariableData objects.

This is a defensive change - it seems unlikely that CSS Variables
can persist beyond the style sheets that create them, but it's also
easy and cheap to ensure that resolved CSS variables pin their
backing strings.

It's worth noting that resolved CSS Variables can *only* reference
either their own string, or strings from other *already resolved*
variables.

BUG=561872
==========

to

==========
Store custom property backing strings in resolved CSSVariableData objects.

This is a defensive change - it seems unlikely that CSS Variables
can persist beyond the style sheets that create them, but it's also
easy and cheap to ensure that resolved CSS variables pin their
backing strings.

It's worth noting that resolved CSS Variables can *only* reference
either their own string, or strings from other *already resolved*
variables.

BUG=465126
==========

[shans, 2015-12-03 03:56:01]

The CQ bit was checked by shans@chromium.org

[commit-bot: I haz the power, 2015-12-03 03:56:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1498713002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1498713002/1

[alancutter (OOO until 2018), 2015-12-03 04:14:11]

alancutter@chromium.org changed reviewers:
+ alancutter@chromium.org

[alancutter (OOO until 2018), 2015-12-03 04:14:12]

https://codereview.chromium.org/1498713002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/css/CSSVariableData.h (right):

https://codereview.chromium.org/1498713002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/css/CSSVariableData.h:42: // this will
potentially reference.
We should update the comment to the new lifetime guarantee rationale now that we
no longer depend on the relative life span of CSSCustomPropertyDeclarations.

[shans, 2015-12-03 04:29:55]

https://codereview.chromium.org/1498713002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/css/CSSVariableData.h (right):

https://codereview.chromium.org/1498713002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/css/CSSVariableData.h:42: // this will
potentially reference.
On 2015/12/03 at 04:14:12, alancutter wrote:
> We should update the comment to the new lifetime guarantee rationale now that
we no longer depend on the relative life span of CSSCustomPropertyDeclarations.

This comment isn't wrong..

I think I'll submit (probably as a separate patch) some fairly extensive
documentation improvements.

[commit-bot: I haz the power, 2015-12-03 05:16:56]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-12-03 05:17:33]

Description was changed from

==========
Store custom property backing strings in resolved CSSVariableData objects.

This is a defensive change - it seems unlikely that CSS Variables
can persist beyond the style sheets that create them, but it's also
easy and cheap to ensure that resolved CSS variables pin their
backing strings.

It's worth noting that resolved CSS Variables can *only* reference
either their own string, or strings from other *already resolved*
variables.

BUG=465126
==========

to

==========
Store custom property backing strings in resolved CSSVariableData objects.

This is a defensive change - it seems unlikely that CSS Variables
can persist beyond the style sheets that create them, but it's also
easy and cheap to ensure that resolved CSS variables pin their
backing strings.

It's worth noting that resolved CSS Variables can *only* reference
either their own string, or strings from other *already resolved*
variables.

BUG=465126

Committed: https://crrev.com/e9e72810a4bd7900a69f86f40884ddb310189a92
Cr-Commit-Position: refs/heads/master@{#362913}
==========

[commit-bot: I haz the power, 2015-12-03 05:17:38]

Patchset 1 (id:??) landed as
https://crrev.com/e9e72810a4bd7900a69f86f40884ddb310189a92
Cr-Commit-Position: refs/heads/master@{#362913}