[Sync] Allow sync start without sign-in if the local sync backend is on.

components/suggestions/suggestions_service_impl.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/suggestions/suggestions_service_impl.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/feature_list.h"
@@ skipping 48 matching lines @@
   // Behavior: Update suggestions from the server. Serve from cache on timeout.
   INITIALIZED_ENABLED_HISTORY,
 
   // State: Sync service is disabled or history sync is disabled.
   // Behavior: Do not issue a server request. Clear the cache. Serve empty
   //     suggestions.
   SYNC_OR_HISTORY_SYNC_DISABLED,
 };
 
 SyncState GetSyncState(syncer::SyncService* sync) {
-  if (!sync || !sync->CanSyncStart())
+  if (!sync || !sync->CanSyncStart() || sync->IsLocalSyncEnabled())
     return SYNC_OR_HISTORY_SYNC_DISABLED;
   if (!sync->IsSyncActive() || !sync->ConfigurationDone())
     return NOT_INITIALIZED_ENABLED;
   return sync->GetActiveDataTypes().Has(syncer::HISTORY_DELETE_DIRECTIVES)
              ? INITIALIZED_ENABLED_HISTORY
              : SYNC_OR_HISTORY_SYNC_DISABLED;
 }
 
 // Used to UMA log the state of the last response from the server.
 enum SuggestionsResponseState {
@@ skipping 478 matching lines @@
     scheduling_delay_ = TimeDelta::FromSeconds(kDefaultSchedulingDelaySec);
   } else {
     TimeDelta candidate_delay =
         scheduling_delay_ * kSchedulingBackoffMultiplier;
     if (candidate_delay < TimeDelta::FromSeconds(kSchedulingMaxDelaySec))
       scheduling_delay_ = candidate_delay;
   }
 }
 
 }  // namespace suggestions