cc: Make SingleThreadProxy ignore commit requests inside Layout().

cc: Make SingleThreadProxy ignore commit requests inside Layout().

This makes the SingleThreadProxy match the behaviour of ThreadProxy and
ensures that when the embedder is doing Layout() if it changes things
that would cause a commit, those things will already happen in the
upcoming commit so it does not schedule a second commit afterward.

R=enne,vmpstr
BUG=466426
Committed: https://crrev.com/fcdaba12b78f0ec947511dd74a418a7754e50c7c
Cr-Commit-Position: refs/heads/master@{#326884}

[danakj, 2015-04-23 22:19:21]

danakj@chromium.org changed reviewers:
+ vmpstr@chromium.org

[enne (OOO), 2015-04-23 22:24:56]

lgtm

[danakj, 2015-04-23 22:27:31]

The CQ bit was checked by danakj@chromium.org

[commit-bot: I haz the power, 2015-04-23 22:27:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1061993009/1

[commit-bot: I haz the power, 2015-04-24 00:40:47]

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

[commit-bot: I haz the power, 2015-04-24 00:40:48]

Try jobs failed on following builders:
  linux_chromium_asan_rel on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[danakj, 2015-04-24 19:04:07]

PTAL, a few more changes:

1) Create scheduler when STP is created, so that scheduler_on_impl_thread_ is
consistent, and so that SetNeedsCommit() before the scheduler is started still
tells the scheduler about the request.

2) Set commit_requested_ to false if beginmainframe early outs, similar to
thread proxy.

[enne (OOO), 2015-04-24 19:06:59]

lgtm still

[danakj, 2015-04-24 20:10:25]

The CQ bit was checked by danakj@chromium.org

[danakj, 2015-04-24 20:10:25]

The patchset sent to the CQ was uploaded after l-g-t-m from enne@chromium.org
Link to the patchset: https://codereview.chromium.org/1061993009/#ps40001
(title: "stp-snc: fixtest")

[commit-bot: I haz the power, 2015-04-24 20:11:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1061993009/40001

[commit-bot: I haz the power, 2015-04-24 20:18:55]

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

[commit-bot: I haz the power, 2015-04-24 20:18:55]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[danakj, 2015-04-24 21:02:02]

danakj@chromium.org changed reviewers:
+ sievers@chromium.org

[danakj, 2015-04-24 21:02:03]

+sievers for content/

[no sievers, 2015-04-24 21:03:13]

On 2015/04/24 21:02:03, danakj wrote:
> +sievers for content/

lgtm

[danakj, 2015-04-24 21:03:51]

The CQ bit was checked by danakj@chromium.org

[commit-bot: I haz the power, 2015-04-24 21:04:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1061993009/40001

[commit-bot: I haz the power, 2015-04-24 21:41:58]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-04-24 21:42:53]

Patchset 3 (id:??) landed as
https://crrev.com/fcdaba12b78f0ec947511dd74a418a7754e50c7c
Cr-Commit-Position: refs/heads/master@{#326884}