sync: Remove unnecessary DCHECKs from about:sync

sync: Remove unnecessary DCHECKs from about:sync

Removes a DCHECK in SyncBackendHostImpl that would trigger if we tried
to register to observe protocol events (ie. open the about:sync page)
before initialization was complete.  This DCHECK was unnecessary, since
there should be no harm in registering an observer before the sync
backend is initialized.  Allowing early registration makes the protocol
logs useful for debugging more kinds of issues.

BUG=365806
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=266643

[rlarocque, 2014-04-24 19:08:25]

Please review.

[tim (not reviewing), 2014-04-24 19:22:09]

thanks! LGTM

[rlarocque, 2014-04-24 19:43:20]

The CQ bit was checked by rlarocque@chromium.org

[commit-bot: I haz the power, 2014-04-24 21:48:20]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rlarocque@chromium.org/254563005/1

[commit-bot: I haz the power, 2014-04-24 22:39:53]

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

[commit-bot: I haz the power, 2014-04-24 22:39:53]

Try jobs failed on following builders:
  tryserver.chromium on linux_chromium_clang_dbg

[rlarocque, 2014-04-24 22:46:31]

The CQ bit was checked by rlarocque@chromium.org

[commit-bot: I haz the power, 2014-04-24 22:47:17]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rlarocque@chromium.org/254563005/1

[commit-bot: I haz the power, 2014-04-25 00:20:26]

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

[commit-bot: I haz the power, 2014-04-25 00:20:27]

Try jobs failed on following builders:
  tryserver.chromium on win_chromium_rel

[rlarocque, 2014-04-25 01:05:54]

The CQ bit was checked by rlarocque@chromium.org

[commit-bot: I haz the power, 2014-04-25 01:06:49]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rlarocque@chromium.org/254563005/1

[commit-bot: I haz the power, 2014-04-25 03:04:10]

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

[commit-bot: I haz the power, 2014-04-25 03:04:10]

Try jobs failed on following builders:
  tryserver.chromium on win_chromium_rel

[rlarocque, 2014-04-28 17:24:55]

The CQ bit was checked by rlarocque@chromium.org

[commit-bot: I haz the power, 2014-04-28 17:25:54]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rlarocque@chromium.org/254563005/1

[commit-bot: I haz the power, 2014-04-28 20:07:20]

Change committed as 266643