Remove gcm channel state supported by sync service.

sync/internal_api/public/util/experiments.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SYNC_UTIL_EXPERIMENTS_
 #define SYNC_UTIL_EXPERIMENTS_
 
 #include <string>
 
 #include "sync/internal_api/public/base/model_type.h"
 
 namespace syncer {
 
 const char kFaviconSyncTag[] = "favicon_sync";
 const char kPreCommitUpdateAvoidanceTag[] = "pre_commit_update_avoidance";
-const char kGCMChannelTag[] = "gcm_channel";
 const char kEnhancedBookmarksTag[] = "enhanced_bookmarks";
 const char kGCMInvalidationsTag[] = "gcm_invalidations";
 const char kWalletSyncTag[] = "wallet_sync";
 
 // A structure to hold the enable status of experimental sync features.
 struct Experiments {
-  enum GCMChannelState {
-    UNSET,
-    SUPPRESSED,
-    ENABLED,
-  };
-
   Experiments()
       : favicon_sync_limit(200),
-        gcm_channel_state(UNSET),
         enhanced_bookmarks_enabled(false),
         gcm_invalidations_enabled(true),  // By default GCM channel is enabled.
         wallet_sync_enabled(false) {}
 
   bool Matches(const Experiments& rhs) {
     return (favicon_sync_limit == rhs.favicon_sync_limit &&
-            gcm_channel_state == rhs.gcm_channel_state &&
             enhanced_bookmarks_enabled == rhs.enhanced_bookmarks_enabled &&
             enhanced_bookmarks_ext_id == rhs.enhanced_bookmarks_ext_id &&
             gcm_invalidations_enabled == rhs.gcm_invalidations_enabled &&
             wallet_sync_enabled == rhs.wallet_sync_enabled);
   }
 
   // The number of favicons that a client is permitted to sync.
   int favicon_sync_limit;
 
-  // Enable state of the GCM channel.
-  GCMChannelState gcm_channel_state;
-
   // Enable the enhanced bookmarks sync datatype.
   bool enhanced_bookmarks_enabled;
 
   // Enable invalidations over GCM channel.
   bool gcm_invalidations_enabled;
 
   // Enhanced bookmarks extension id.
   std::string enhanced_bookmarks_ext_id;
 
   // Enable the Wallet Autofill sync datatype.
   bool wallet_sync_enabled;
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_UTIL_EXPERIMENTS_