Dirty tree scopes are always a subset of active tree scopes.

Dirty tree scopes are always a subset of active tree scopes.

No need to walk dirty tree scopes when clearing media dependent rule
sets after walking the active tree scopes.

Also clear m_dirtyTreeScopes in StyleEngine::detachFromDocument.
Currently, m_dirtyTreeScopes are synchronously updated and cleared
right after they are marked dirty, but that is supposed to change.

BUG=567021
Committed: https://crrev.com/dba3b6817d37e512d4722aa642353b7d48db1a7d
Cr-Commit-Position: refs/heads/master@{#381909}

[rune, 2016-03-11 14:09:22]

The CQ bit was checked by rune@opera.com to run a CQ dry run

[commit-bot: I haz the power, 2016-03-11 14:09:39]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1786663003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1786663003/1

[commit-bot: I haz the power, 2016-03-11 16:15:45]

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

[commit-bot: I haz the power, 2016-03-11 16:15:46]

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_...)

[rune, 2016-03-11 18:18:28]

rune@opera.com changed reviewers:
+ esprehn@chromium.org

[rune, 2016-03-17 12:56:50]

ptal

[esprehn, 2016-03-18 05:02:24]

lgtm

[rune, 2016-03-18 06:49:30]

The CQ bit was checked by rune@opera.com

[commit-bot: I haz the power, 2016-03-18 06:49:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1786663003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1786663003/1

[commit-bot: I haz the power, 2016-03-18 07:56:49]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-18 07:58:31]

Description was changed from

==========
Dirty tree scopes are always a subset of active tree scopes.

No need to walk dirty tree scopes when clearing media dependent rule
sets after walking the active tree scopes.

Also clear m_dirtyTreeScopes in StyleEngine::detachFromDocument.
Currently, m_dirtyTreeScopes are synchronously updated and cleared
right after they are marked dirty, but that is supposed to change.

BUG=567021
==========

to

==========
Dirty tree scopes are always a subset of active tree scopes.

No need to walk dirty tree scopes when clearing media dependent rule
sets after walking the active tree scopes.

Also clear m_dirtyTreeScopes in StyleEngine::detachFromDocument.
Currently, m_dirtyTreeScopes are synchronously updated and cleared
right after they are marked dirty, but that is supposed to change.

BUG=567021

Committed: https://crrev.com/dba3b6817d37e512d4722aa642353b7d48db1a7d
Cr-Commit-Position: refs/heads/master@{#381909}
==========

[commit-bot: I haz the power, 2016-03-18 07:58:32]

Patchset 1 (id:??) landed as
https://crrev.com/dba3b6817d37e512d4722aa642353b7d48db1a7d
Cr-Commit-Position: refs/heads/master@{#381909}