Remove unused constant.

Bug: 799483
Change-Id: I9411d141492ae3db3f6baf413b31c7daa099b3a0
Reviewed-on: https://chromium-review.googlesource.com/918801Reviewed-by: Peter Beverloo <peter@chromium.org>
Commit-Queue: Peter Beverloo <peter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#536702}

components/gcm_driver/features.cc

@@ -18,7 +18,6 @@ const base::Feature kInvalidateTokenFeature{"GCMTokenInvalidAfterDays",
                                             base::FEATURE_DISABLED_BY_DEFAULT};
 const char kParamNameTokenInvalidationPeriodDays[] =
     "token_invalidation_period";
-const char kGroupName[] = "token_validity_data";
 // A token invalidation period of 0 means the feature is disabled, and the
 // GCM token never becomes stale.
 const int kDefaultTokenInvalidationPeriod = 7;

components/gcm_driver/features.h

@@ -13,7 +13,6 @@ namespace features {
 
 extern const base::Feature kInvalidateTokenFeature;
 extern const char kParamNameTokenInvalidationPeriodDays[];
-extern const char kGroupName[];
 
 // The period after which the GCM token becomes stale.
 base::TimeDelta GetTokenInvalidationInterval();