Revert of Flag covering Rollback removed.

Revert of Flag covering Rollback removed. (https://codereview.chromium.org/326373002/)

Reason for revert:
This feature is postponed to M38.

Original issue's description:
> Flag covering Rollback removed.
> 
> BUG=368860
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=277725

TBR=merkulova@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=368860

[Nikita (slow), 2014-06-23 16:27:02]

Created Revert of Flag covering Rollback removed.

[Nikita (slow), 2014-06-23 16:27:39]

On 2014/06/23 16:27:02, Nikita Kostylev wrote:
> Created Revert of Flag covering Rollback removed.

See https://code.google.com/p/chromium/issues/detail?id=294200#c40

[commit-bot: I haz the power, 2014-06-23 16:27:42]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/nkostylev@chromium.org/344963003/1

[commit-bot: I haz the power, 2014-06-23 16:28:44]

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

[commit-bot: I haz the power, 2014-06-23 16:28:45]

Failed to apply patch for chromeos/chromeos_switches.h:
While running patch -p1 --forward --force --no-backup-if-mismatch;
  patching file chromeos/chromeos_switches.h
  Hunk #1 succeeded at 36 (offset 1 line).
  Hunk #2 FAILED at 42.
  1 out of 2 hunks FAILED -- saving rejects to file
chromeos/chromeos_switches.h.rej

Patch:       chromeos/chromeos_switches.h
Index: chromeos/chromeos_switches.h
diff --git a/chromeos/chromeos_switches.h b/chromeos/chromeos_switches.h
index
20d3625905a75ce69f1431d4aa8c311d9b29cc45..ec0dbf4e858b376ca6e973fd018c040525c6efa0
100644
--- a/chromeos/chromeos_switches.h
+++ b/chromeos/chromeos_switches.h
@@ -35,7 +35,6 @@
 CHROMEOS_EXPORT extern const char kDisableNewChannelSwitcherUI[];
 CHROMEOS_EXPORT extern const char kDisableNewKioskUI[];
 CHROMEOS_EXPORT extern const char kDisableQuickofficeComponentApp[];
-CHROMEOS_EXPORT extern const char kDisableRollbackOption[];
 CHROMEOS_EXPORT extern const char kDisableVolumeAdjustSound[];
 CHROMEOS_EXPORT extern const char kEnableCarrierSwitching[];
 CHROMEOS_EXPORT extern const char kEnableChromeVoxNext[];
@@ -43,6 +42,7 @@
 CHROMEOS_EXPORT extern const char kEnableEmbeddedSignin[];
 CHROMEOS_EXPORT extern const char kEnableExtensionAssetsSharing[];
 CHROMEOS_EXPORT extern const char kEnableFileManagerMTP[];
+CHROMEOS_EXPORT extern const char kEnableRollbackOption[];
 CHROMEOS_EXPORT extern const char kEnableHIDDetectionOnOOBE[];
 CHROMEOS_EXPORT extern const char kEnableKioskMode[];
 CHROMEOS_EXPORT extern const char kEnableNetworkPortalNotification[];

[Nikita (slow), 2014-06-24 08:01:54]

I'll do a proper revert on branch instead.