Revert of Sync commit errors should temporarily re-enable trigger pre-commit getupdates

Revert of Sync commit errors should temporarily re-enable trigger pre-commit getupdates (patchset #2 id:20001 of https://codereview.chromium.org/905853002/)

Reason for revert:
Looks like this broke the build

Undefined symbols for architecture armv7:
  "syncer::sessions::test_util::SimulateDownloadUpdatesFailed(syncer::EnumSet<syncer::ModelType, (syncer::ModelType)2, (syncer::ModelType)33>, syncer::sessions::NudgeTracker const&, syncer::sessions::SyncSession*)", referenced from:
      syncer::BackoffTriggersSyncSchedulerTest_FailDownloadOnceThenSucceed_Test::TestBody() in sync_scheduler_unittest.o
      syncer::BackoffTriggersSyncSchedulerTest_FailDownloadTwice_Test::TestBody() in sync_scheduler_unittest.o
      syncer::SyncSchedulerTest_FailedRetry_Test::TestBody() in sync_scheduler_unittest.o

Original issue's description:
> Sync commit errors should temporarily re-enable
> trigger pre-commit getupdates
>
> Add a boolean variable in class DataTypeTracker, so every
> time when a data type got conflict response from server
> during commit, will set that boolean variable to true, then
> next time sync, GetUpdate will check the boolean to see if
> need to GetUpdate to resolve conflict locally.
>
> BUG=324893
>
> Committed: https://crrev.com/21f43c5af27e24c34565df26bb51fcc704c97597
> Cr-Commit-Position: refs/heads/master@{#315339}

TBR=zea@chromium.org,stanisc@chromium.org,maniscalco@chromium.org,pvalenzuela@chromium.org,gangwu@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=324893
Committed: https://crrev.com/796a0ab344091f0782693b636206286e4784a078
Cr-Commit-Position: refs/heads/master@{#315346}

[Ryan Hamilton, 2015-02-09 18:31:02]

Created Revert of Sync commit errors should temporarily re-enable trigger
pre-commit getupdates

[commit-bot: I haz the power, 2015-02-09 18:32:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/891123003/1

[commit-bot: I haz the power, 2015-02-09 18:33:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-09 18:33:42]

Patchset 1 (id:??) landed as
https://crrev.com/796a0ab344091f0782693b636206286e4784a078
Cr-Commit-Position: refs/heads/master@{#315346}