sync: Remove SyncSourceInfo

sync/engine/syncer.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_ENGINE_SYNCER_H_
 #define SYNC_ENGINE_SYNCER_H_
 
 #include <utility>
 #include <vector>
 
@@ skipping 25 matching lines @@
   typedef std::vector<int64> UnsyncedMetaHandles;
 
   Syncer();
   virtual ~Syncer();
 
   // Called by other threads to tell the syncer to stop what it's doing
   // and return early from SyncShare, if possible.
   bool ExitRequested();
   void RequestEarlyExit();
 
+  // Fetches and applies updates, resolves conflicts and commits local changes
+  // for |request_types| as necessary until client and server states are in
+  // sync.  The |nudge_tracker| contains state that describes why the client is
+  // out of sync and what must be done to bring it back into sync.
   virtual bool NormalSyncShare(ModelTypeSet request_types,
                                const sessions::NudgeTracker& nudge_tracker,
                                sessions::SyncSession* session);
-  virtual bool ConfigureSyncShare(ModelTypeSet request_types,
-                                  sessions::SyncSession* session);
+
+  // Performs an initial download for the |request_types|.  It is assumed that
+  // the specified types have no local state, and that their associated change
+  // processors are in "passive" mode, so none of the downloaded updates will be
+  // applied to the model.  The |source| is sent up to the server for debug
+  // purposes.  It describes the reson for performing this initial download.
+  virtual bool ConfigureSyncShare(
+      ModelTypeSet request_types,
+      sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source,
+      sessions::SyncSession* session);
+
+  // Requests to download updates for the |request_types|.  For a well-behaved
+  // client with a working connection to the invalidations server, this should
+  // be unnecessary.  It may be invoked periodically to try to keep the client
+  // in sync despite bugs or transient failures.
   virtual bool PollSyncShare(ModelTypeSet request_types,
                              sessions::SyncSession* session);
 
  private:
   void ApplyUpdates(sessions::SyncSession* session);
   bool DownloadAndApplyUpdates(
       sessions::SyncSession* session,
       base::Callback<SyncerError(void)> download_fn);
 
   void HandleCycleBegin(sessions::SyncSession* session);
-  bool HandleCycleEnd(sessions::SyncSession* session);
+  bool HandleCycleEnd(
+      sessions::SyncSession* session,
+      sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source);
 
   bool early_exit_requested_;
   base::Lock early_exit_requested_lock_;
 
   friend class SyncerTest;
   FRIEND_TEST_ALL_PREFIXES(SyncerTest, NameClashWithResolver);
   FRIEND_TEST_ALL_PREFIXES(SyncerTest, IllegalAndLegalUpdates);
   FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestCommitListOrderingAndNewParent);
   FRIEND_TEST_ALL_PREFIXES(SyncerTest,
                            TestCommitListOrderingAndNewParentAndChild);
@@ skipping 12 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(SyncerTest, DeletingEntryWithLocalEdits);
   FRIEND_TEST_ALL_PREFIXES(EntryCreatedInNewFolderTest,
                            EntryCreatedInNewFolderMidSync);
 
   DISALLOW_COPY_AND_ASSIGN(Syncer);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_ENGINE_SYNCER_H_