Simulate transient error and verify exponential backoff.

chrome/browser/sync/engine/syncer.h

 // Copyright (c) 2011 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 CHROME_BROWSER_SYNC_ENGINE_SYNCER_H_
 #define CHROME_BROWSER_SYNC_ENGINE_SYNCER_H_
 #pragma once
 
 #include <utility>
 #include <vector>
@@ skipping 69 matching lines @@
   // 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();
 
   // Runs a sync cycle from |first_step| to |last_step|.
   virtual void SyncShare(sessions::SyncSession* session,
                          SyncerStep first_step,
                          SyncerStep last_step);
 
+  class ScopedSyncStartStopTracker {
+   public:
+    explicit ScopedSyncStartStopTracker(sessions::SyncSession* session);
+    ~ScopedSyncStartStopTracker();
+   private:
+    sessions::SyncSession* session_;
+
+    DISALLOW_COPY_AND_ASSIGN(ScopedSyncStartStopTracker);
+  };
+
  private:
   // Implements the PROCESS_CLIENT_COMMAND syncer step.
   void ProcessClientCommand(sessions::SyncSession* session);
 
   bool early_exit_requested_;
   base::Lock early_exit_requested_lock_;
 
   ConflictResolver resolver_;
 
   // A callback hook used in unittests to simulate changes between conflict set
@@ skipping 28 matching lines @@
 };
 
 // Utility function declarations.
 void CopyServerFields(syncable::Entry* src, syncable::MutableEntry* dest);
 void ClearServerData(syncable::MutableEntry* entry);
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_ENGINE_SYNCER_H_