Refactor PropertyTreeState to use RefPtrs

Refactor PropertyTreeState to use RefPtrs

PropertyTreeState stores the total state of the property trees at some
given time. At the moment this is only used for FrameView, but I'd like
to use PropertyTreeState in LocalBorderBoxProperties in the future.

The purpose of this patch is twofold:
1) Guard against use-after-free bugs as we add support for incremental
updates to the property trees.
2) Prepare to refactor LocalBorderBoxProperties (which uses RefPtrs) to
use PropertyTreeState.

BUG=645615
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/f0ebdb54d79437c44dc8664f011aaa6a7bb49f5f
Cr-Commit-Position: refs/heads/master@{#421943}

[pdr., 2016-09-29 02:05:49]

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

[commit-bot: I haz the power, 2016-09-29 02:06:17]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-29 03:19:34]

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

[commit-bot: I haz the power, 2016-09-29 03:19:34]

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

[pdr., 2016-09-29 18:11:35]

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

[chrishtr, 2016-09-29 20:40:45]

The CQ bit was checked by chrishtr@chromium.org

[chrishtr, 2016-09-29 20:40:45]

lgtm

[commit-bot: I haz the power, 2016-09-29 20:41:10]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-29 21:49:00]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-29 21:52:13]

Description was changed from

==========
Refactor PropertyTreeState to use RefPtrs

PropertyTreeState stores the total state of the property trees at some
given time. At the moment this is only used for FrameView, but I'd like
to use PropertyTreeState in LocalBorderBoxProperties in the future.

The purpose of this patch is twofold:
1) Guard against use-after-free bugs as we add support for incremental
updates to the property trees.
2) Prepare to refactor LocalBorderBoxProperties (which uses RefPtrs) to
use PropertyTreeState.

BUG=645615
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Refactor PropertyTreeState to use RefPtrs

PropertyTreeState stores the total state of the property trees at some
given time. At the moment this is only used for FrameView, but I'd like
to use PropertyTreeState in LocalBorderBoxProperties in the future.

The purpose of this patch is twofold:
1) Guard against use-after-free bugs as we add support for incremental
updates to the property trees.
2) Prepare to refactor LocalBorderBoxProperties (which uses RefPtrs) to
use PropertyTreeState.

BUG=645615
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/f0ebdb54d79437c44dc8664f011aaa6a7bb49f5f
Cr-Commit-Position: refs/heads/master@{#421943}
==========

[commit-bot: I haz the power, 2016-09-29 21:52:14]

Patchset 1 (id:??) landed as
https://crrev.com/f0ebdb54d79437c44dc8664f011aaa6a7bb49f5f
Cr-Commit-Position: refs/heads/master@{#421943}