Remove unnecessary use of CrossThreadPersistent<>.

Remove unnecessary use of CrossThreadPersistent<>.

The CompositorMutatorImpl object that WebFrameWidgetImpl creates and
controls the lifetime of, should be referenced as a normal Member<>

R=
BUG=

Committed: https://crrev.com/64d9377e8c194ef2c5dc12c836620b9924a9af5b
Cr-Commit-Position: refs/heads/master@{#399125}

[sof, 2016-06-09 21:10:03]

sigbjornf@opera.com changed reviewers:
+ oilpan-reviews@chromium.org

[sof, 2016-06-09 21:10:03]

please take a look.

[haraken, 2016-06-09 23:34:26]

But this is a cross-thread reference, right? keishi@ is planning to replace
cross-thread references with CrossThreadPersistent when we enable the per-thread
heap.

[sof, 2016-06-10 05:12:53]

On 2016/06/09 23:34:26, haraken wrote:
> But this is a cross-thread reference, right? keishi@ is planning to replace
> cross-thread references with CrossThreadPersistent when we enable the
per-thread
> heap.

It's created, owned and passed to another object created on the main thread..?
If someone passes that to a compositor work, that would represent a cross-thread
pointer.

[haraken, 2016-06-10 05:21:21]

On 2016/06/10 05:12:53, sof wrote:
> On 2016/06/09 23:34:26, haraken wrote:
> > But this is a cross-thread reference, right? keishi@ is planning to replace
> > cross-thread references with CrossThreadPersistent when we enable the
> per-thread
> > heap.
> 
> It's created, owned and passed to another object created on the main thread..?
> If someone passes that to a compositor work, that would represent a
cross-thread
> pointer.

ah, makes sense. LGTM.

[sof, 2016-06-10 06:30:04]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2016-06-10 06:30:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2056833003/1

[commit-bot: I haz the power, 2016-06-10 06:46:46]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-10 06:49:00]

Description was changed from

==========
Remove unnecessary use of CrossThreadPersistent<>.

The CompositorMutatorImpl object that WebFrameWidgetImpl creates and
controls the lifetime of, should be referenced as a normal Member<>

R=
BUG=
==========

to

==========
Remove unnecessary use of CrossThreadPersistent<>.

The CompositorMutatorImpl object that WebFrameWidgetImpl creates and
controls the lifetime of, should be referenced as a normal Member<>

R=
BUG=

Committed: https://crrev.com/64d9377e8c194ef2c5dc12c836620b9924a9af5b
Cr-Commit-Position: refs/heads/master@{#399125}
==========

[commit-bot: I haz the power, 2016-06-10 06:49:01]

Patchset 1 (id:??) landed as
https://crrev.com/64d9377e8c194ef2c5dc12c836620b9924a9af5b
Cr-Commit-Position: refs/heads/master@{#399125}

[flackr, 2016-06-10 14:45:14]

On 2016/06/10 at 05:12:53, sigbjornf wrote:
> On 2016/06/09 23:34:26, haraken wrote:
> > But this is a cross-thread reference, right? keishi@ is planning to replace
> > cross-thread references with CrossThreadPersistent when we enable the
per-thread
> > heap.
> 
> It's created, owned and passed to another object created on the main thread..?
If someone passes that to a compositor work, that would represent a cross-thread
pointer.

It is passed to the compositor thread through the WebLayerTreeView plumbing. It
is actually held indirectly by LayerTreeHostImpl's OwnPtr<LayerTreeMutator>
https://cs.chromium.org/chromium/src/cc/trees/layer_tree_host_impl.h?q=LayerT...
which holds a Persistent<CompositorMutator> of the CompositorMutatorImpl here:
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/platform/graph...