SuggestionsService: don't automatically fetch on startup

components/suggestions/suggestions_service_impl.h

 // Copyright 2016 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 COMPONENTS_SUGGESTIONS_SUGGESTIONS_SERVICE_IMPL_H_
 #define COMPONENTS_SUGGESTIONS_SUGGESTIONS_SERVICE_IMPL_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/callback_list.h"
+#include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/optional.h"
 #include "base/scoped_observer.h"
 #include "base/threading/thread_checker.h"
 #include "base/time/time.h"
 #include "components/signin/core/browser/access_token_fetcher.h"
 #include "components/suggestions/proto/suggestions.pb.h"
 #include "components/suggestions/suggestions_service.h"
@@ skipping 58 matching lines @@
 
   // Register SuggestionsService related prefs in the Profile prefs.
   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
 
  private:
   friend class SuggestionsServiceTest;
   FRIEND_TEST_ALL_PREFIXES(SuggestionsServiceTest, FetchSuggestionsData);
   FRIEND_TEST_ALL_PREFIXES(SuggestionsServiceTest, IgnoresNoopSyncChange);
   FRIEND_TEST_ALL_PREFIXES(SuggestionsServiceTest,
                            IgnoresUninterestingSyncChange);
+  FRIEND_TEST_ALL_PREFIXES(SuggestionsServiceTest, DoesNotFetchOnStartup);
   FRIEND_TEST_ALL_PREFIXES(SuggestionsServiceTest,
                            FetchSuggestionsDataSyncNotInitializedEnabled);
   FRIEND_TEST_ALL_PREFIXES(SuggestionsServiceTest,
                            FetchSuggestionsDataSyncDisabled);
   FRIEND_TEST_ALL_PREFIXES(SuggestionsServiceTest,
                            FetchSuggestionsDataNoAccessToken);
   FRIEND_TEST_ALL_PREFIXES(SuggestionsServiceTest,
                            IssueRequestIfNoneOngoingError);
   FRIEND_TEST_ALL_PREFIXES(SuggestionsServiceTest,
                            IssueRequestIfNoneOngoingResponseNotOK);
@@ skipping 22 matching lines @@
     //     enabled.
     // Behavior: Update suggestions from the server on FetchSuggestionsData().
     INITIALIZED_ENABLED_HISTORY,
 
     // State: Sync service is disabled or history sync is disabled.
     // Behavior: Do not issue server requests. Clear the cache. Serve empty
     //     suggestions.
     SYNC_OR_HISTORY_SYNC_DISABLED,
   };
 
+  // The action that should be taken as the result of a RefreshSyncState call.
+  enum RefreshAction { NO_ACTION, FETCH_SUGGESTIONS, CLEAR_SUGGESTIONS };
+
   // Helpers to build the various suggestions URLs. These are static members
   // rather than local functions in the .cc file to make them accessible to
   // tests.
   static GURL BuildSuggestionsURL();
   static std::string BuildSuggestionsBlacklistURLPrefix();
   static GURL BuildSuggestionsBlacklistURL(const GURL& candidate_url);
   static GURL BuildSuggestionsBlacklistClearURL();
 
   // Computes the appropriate SyncState from |sync_service_|.
   SyncState ComputeSyncState() const;
 
-  // Re-computes |sync_state_| from the sync service. Returns whether
-  // |sync_state_| was changed.
-  bool RefreshSyncState();
+  // Re-computes |sync_state_| from the sync service. Returns the action that
+  // should be taken in response.
+  RefreshAction RefreshSyncState() WARN_UNUSED_RESULT;
 
   // syncer::SyncServiceObserver implementation.
   void OnStateChanged(syncer::SyncService* sync) override;
 
   // Sets default timestamp for suggestions which do not have expiry timestamp.
   void SetDefaultExpiryTimestamp(SuggestionsProfile* suggestions,
                                  int64_t timestamp_usec);
 
   // Issues a network request if there isn't already one happening.
   void IssueRequestIfNoneOngoing(const GURL& url);
@@ skipping 82 matching lines @@
 
   // For callbacks may be run after destruction.
   base::WeakPtrFactory<SuggestionsServiceImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SuggestionsServiceImpl);
 };
 
 }  // namespace suggestions
 
 #endif  // COMPONENTS_SUGGESTIONS_SUGGESTIONS_SERVICE_IMPL_H_