Move preferred stylesheet logic into StyleEngine.

Move preferred stylesheet logic into StyleEngine.

To understand the code better:

We don't support selecting alternate stylesheets in Blink, although the
API for Document.selectedStylesheetSet is present. The way it works, is
that the effective selected stylesheet set is either empty or the
preferred set. Setting selectedStylesheetSet has no effect.

This CL should not impose any functional changes, but a resolverChanged
with no effect has been removed.

The next step for async active stylesheet update is to move the setting
of the preferred set name to where the the dom mutations happen as the
order of mutations is what defines which stylesheet title has
precedence.

BUG=567021
Committed: https://crrev.com/bffd0dd4e962fb31897082a9b9e34e5bb1a7f331
Cr-Commit-Position: refs/heads/master@{#379762}

[rune, 2016-03-07 13:37:41]

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

[commit-bot: I haz the power, 2016-03-07 13:37:54]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1769903002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1769903002/1

[commit-bot: I haz the power, 2016-03-07 15:02:18]

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

[commit-bot: I haz the power, 2016-03-07 15:02:19]

Dry run: This issue passed the CQ dry run.

[rune, 2016-03-07 19:22:43]

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

[esprehn, 2016-03-08 05:57:46]

The CQ bit was checked by esprehn@chromium.org

[esprehn, 2016-03-08 05:57:46]

lgtm

[commit-bot: I haz the power, 2016-03-08 05:57:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1769903002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1769903002/1

[commit-bot: I haz the power, 2016-03-08 06:05:32]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-08 06:07:57]

Description was changed from

==========
Move preferred stylesheet logic into StyleEngine.

To understand the code better:

We don't support selecting alternate stylesheets in Blink, although the
API for Document.selectedStylesheetSet is present. The way it works, is
that the effective selected stylesheet set is either empty or the
preferred set. Setting selectedStylesheetSet has no effect.

This CL should not impose any functional changes, but a resolverChanged
with no effect has been removed.

The next step for async active stylesheet update is to move the setting
of the preferred set name to where the the dom mutations happen as the
order of mutations is what defines which stylesheet title has
precedence.

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

to

==========
Move preferred stylesheet logic into StyleEngine.

To understand the code better:

We don't support selecting alternate stylesheets in Blink, although the
API for Document.selectedStylesheetSet is present. The way it works, is
that the effective selected stylesheet set is either empty or the
preferred set. Setting selectedStylesheetSet has no effect.

This CL should not impose any functional changes, but a resolverChanged
with no effect has been removed.

The next step for async active stylesheet update is to move the setting
of the preferred set name to where the the dom mutations happen as the
order of mutations is what defines which stylesheet title has
precedence.

BUG=567021

Committed: https://crrev.com/bffd0dd4e962fb31897082a9b9e34e5bb1a7f331
Cr-Commit-Position: refs/heads/master@{#379762}
==========

[commit-bot: I haz the power, 2016-03-08 06:07:58]

Patchset 1 (id:??) landed as
https://crrev.com/bffd0dd4e962fb31897082a9b9e34e5bb1a7f331
Cr-Commit-Position: refs/heads/master@{#379762}