[SyncFS] Create SyncWorkerTest

[SyncFS] Create SyncWorkerTest and add it in unit_tests.

Most tests look same between SyncEngineTest and SyncWorkerTest.
SyncEngineTest checks communications between SyncEngine and SyncWorker.
SyncWorkerTest checks behavior of each method.


BUG=378621
TEST=./unit_tests --gtest_filter="SyncEngineTest.*:SyncWorkerTest.*"

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=275776

[peria, 2014-06-06 08:03:25]

PTL

[tzik, 2014-06-09 03:45:25]

lgtm

[nhiroki, 2014-06-09 04:03:56]

lgtm

[peria, 2014-06-09 04:06:04]

The CQ bit was checked by peria@chromium.org

[commit-bot: I haz the power, 2014-06-09 04:07:01]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/peria@chromium.org/314303003/30001

[commit-bot: I haz the power, 2014-06-09 05:54:52]

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

[commit-bot: I haz the power, 2014-06-09 06:25:07]

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

[commit-bot: I haz the power, 2014-06-09 06:25:08]

Try jobs failed on following builders:
  android_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_clang_dbg/bui...)

[peria, 2014-06-09 06:36:27]

The CQ bit was checked by peria@chromium.org

[commit-bot: I haz the power, 2014-06-09 06:36:55]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/peria@chromium.org/314303003/30001

[commit-bot: I haz the power, 2014-06-09 06:48:17]

Change committed as 275776