[SyncFS] Initialize SyncWorker when sync is enabled.

[SyncFS] Initialize SyncWorker when sync is enabled.

If a service is enabled after initialization failed,
 SyncEngine didn't try initializing SyncWorker again, and that makes SyncFS stuck.

BUG=402356
Committed: https://crrev.com/d5bf7dd2dc2b752cb0365fc6b2ea376df9adfb2b
Cr-Commit-Position: refs/heads/master@{#292831}

[tzik, 2014-08-21 07:49:08]

PTL

[peria, 2014-08-21 08:34:34]

Could you add a test for this change?

https://codereview.chromium.org/470403004/diff/1/chrome/browser/sync_file_sys...
File chrome/browser/sync_file_system/drive_backend/sync_engine.cc (right):

https://codereview.chromium.org/470403004/diff/1/chrome/browser/sync_file_sys...
chrome/browser/sync_file_system/drive_backend/sync_engine.cc:601:
DCHECK(!sync_enabled_);
nit: This DCHECK looks unnecessary

[tzik, 2014-08-21 09:23:29]

On 2014/08/21 08:34:34, peria wrote:
> Could you add a test for this change?

This will be tested by https://codereview.chromium.org/493043002/
(I'll send this to you for review after revising it.)
Feel free to have this CL hold until another is ready.


> 
>
https://codereview.chromium.org/470403004/diff/1/chrome/browser/sync_file_sys...
> File chrome/browser/sync_file_system/drive_backend/sync_engine.cc (right):
> 
>
https://codereview.chromium.org/470403004/diff/1/chrome/browser/sync_file_sys...
> chrome/browser/sync_file_system/drive_backend/sync_engine.cc:601:
> DCHECK(!sync_enabled_);
> nit: This DCHECK looks unnecessary

[tzik, 2014-08-21 09:23:35]

https://codereview.chromium.org/470403004/diff/1/chrome/browser/sync_file_sys...
File chrome/browser/sync_file_system/drive_backend/sync_engine.cc (right):

https://codereview.chromium.org/470403004/diff/1/chrome/browser/sync_file_sys...
chrome/browser/sync_file_system/drive_backend/sync_engine.cc:601:
DCHECK(!sync_enabled_);
On 2014/08/21 08:34:33, peria wrote:
> nit: This DCHECK looks unnecessary

Done.

[peria, 2014-08-21 09:24:48]

lgtm

[tzik, 2014-08-22 02:46:52]

The CQ bit was checked by tzik@chromium.org

[commit-bot: I haz the power, 2014-08-22 02:47:56]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/tzik@chromium.org/470403004/20001

[commit-bot: I haz the power, 2014-08-22 03:42:57]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_chromium_gn_compile_rel on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_chromiu...)
  android_dbg_tests_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_dbg_tes...)

[commit-bot: I haz the power, 2014-08-22 04:39:03]

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

[commit-bot: I haz the power, 2014-08-22 04:39:04]

Try jobs failed on following builders:
  android_dbg_tests_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_dbg_tes...)

[tzik, 2014-09-01 03:20:43]

The CQ bit was checked by tzik@chromium.org

[commit-bot: I haz the power, 2014-09-01 03:21:03]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/tzik@chromium.org/470403004/40001

[commit-bot: I haz the power, 2014-09-01 04:15:36]

Committed patchset #3 (id:40001) as 3919d961614446a64b9f5ad72e9a266dbd5f2684

[commit-bot: I haz the power, 2014-09-10 03:15:31]

Patchset 3 (id:??) landed as
https://crrev.com/d5bf7dd2dc2b752cb0365fc6b2ea376df9adfb2b
Cr-Commit-Position: refs/heads/master@{#292831}