Complete SyncMessageFilter initialization after SyncChannel initialization

Complete SyncMessageFilter initialization after SyncChannel initialization

This changes SyncChannel to keep track of any SyncMessageFilters it
creates prior to ChannelProxy::Init being called. Once Init completes,
initialization of all tracked SyncMessageFilters is completed by
updating their is_channel_send_thread_safe flag.

BUG=516464
R=jam@chromium.org

Committed: https://crrev.com/29ade1b15c854942b553c446df18ad3f3f46a931
Cr-Commit-Position: refs/heads/master@{#342308}

[Ken Rockot(use gerrit already), 2015-08-06 21:21:10]

Patchset #1 (id:1) has been deleted

[Ken Rockot(use gerrit already), 2015-08-06 21:22:35]

Patchset #1 (id:20001) has been deleted

[jam, 2015-08-06 21:37:04]

lgtm

[Ken Rockot(use gerrit already), 2015-08-06 21:51:16]

The CQ bit was checked by rockot@chromium.org

[Ken Rockot(use gerrit already), 2015-08-06 21:51:16]

The patchset sent to the CQ was uploaded after l-g-t-m from jam@chromium.org
Link to the patchset: https://codereview.chromium.org/1279863004/#ps60001
(title: "eh, vector instead of list")

[commit-bot: I haz the power, 2015-08-06 21:52:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1279863004/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1279863004/60001

[commit-bot: I haz the power, 2015-08-06 23:08:25]

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

[commit-bot: I haz the power, 2015-08-06 23:08:26]

Try jobs failed on following builders:
  win_chromium_x64_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Ken Rockot(use gerrit already), 2015-08-06 23:37:11]

The CQ bit was checked by rockot@chromium.org

[commit-bot: I haz the power, 2015-08-06 23:38:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1279863004/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1279863004/60001

[commit-bot: I haz the power, 2015-08-07 02:32:07]

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

[commit-bot: I haz the power, 2015-08-07 02:32:08]

Try jobs failed on following builders:
  mac_chromium_10.10_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_10.1...)

[Ken Rockot(use gerrit already), 2015-08-07 05:52:39]

The CQ bit was checked by rockot@chromium.org

[commit-bot: I haz the power, 2015-08-07 05:52:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1279863004/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1279863004/60001

[commit-bot: I haz the power, 2015-08-07 06:24:07]

Committed patchset #2 (id:60001)

[commit-bot: I haz the power, 2015-08-07 06:24:42]

Patchset 2 (id:??) landed as
https://crrev.com/29ade1b15c854942b553c446df18ad3f3f46a931
Cr-Commit-Position: refs/heads/master@{#342308}