Skip enhanced bookmarks cluster requests if it's not being used.

components/enhanced_bookmarks/bookmark_server_service.cc

 // Copyright 2014 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.
 
 #include "components/enhanced_bookmarks/bookmark_server_service.h"
 
 #include "base/auto_reset.h"
 #include "components/enhanced_bookmarks/enhanced_bookmark_model.h"
 #include "components/signin/core/browser/profile_oauth2_token_service.h"
 #include "components/signin/core/browser/signin_manager_base.h"
@@ skipping 28 matching lines @@
 void BookmarkServerService::AddObserver(
     BookmarkServerServiceObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void BookmarkServerService::RemoveObserver(
     BookmarkServerServiceObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
+bool BookmarkServerService::MightHaveObservers() {
+  return observers_.might_have_observers();
+}
+
 const BookmarkNode* BookmarkServerService::BookmarkForRemoteId(
     const std::string& remote_id) const {
   return model_->BookmarkForRemoteId(remote_id);
 }
 
 const std::string BookmarkServerService::RemoteIDForBookmark(
     const BookmarkNode* bookmark) const {
   return model_->GetRemoteId(bookmark);
 }
 
@@ skipping 84 matching lines @@
 void BookmarkServerService::EnhancedBookmarkModelShuttingDown() {
   NOTREACHED();
 }
 
 SigninManagerBase* BookmarkServerService::GetSigninManager() {
   DCHECK(signin_manager_);
   return signin_manager_;
 }
 
 }  // namespace enhanced_bookmarks