[SyncFS] Eliminate SyncFileSystemService dependency from SyncProcessRunner

chrome/browser/sync_file_system/sync_process_runner.h

 // Copyright 2013 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_FILE_SYSTEM_SYNC_PROCESS_RUNNER_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_SYNC_PROCESS_RUNNER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/memory/weak_ptr.h"
 #include "base/timer/timer.h"
 #include "chrome/browser/sync_file_system/sync_callbacks.h"
 #include "chrome/browser/sync_file_system/sync_service_state.h"
 
 namespace sync_file_system {
 
 class SyncFileSystemService;
 
 // A base class to schedule a sync.
 // Each subclass must implement StartSync().
 // An instance of this class is supposed to be owned by SyncFileSystemService.
 //
 // Note that multiple SyncProcessRunner doesn't coordinate its sync schedule
 // with each other.
 class SyncProcessRunner {
  public:
+  class Client {
+   public:
+    virtual ~Client() {}
+    virtual void OnSyncIdle() {}
+    virtual SyncServiceState GetSyncServiceState() = 0;
+    virtual SyncFileSystemService* GetSyncService() = 0;
+  };
+
   class TimerHelper {
    public:
     virtual ~TimerHelper() {}
     virtual bool IsRunning() = 0;
     virtual void Start(const tracked_objects::Location& from_here,
                        const base::TimeDelta& delay,
                        const base::Closure& closure) = 0;
 
    protected:
     TimerHelper() {}
   };
 
   SyncProcessRunner(const std::string& name,
-                    SyncFileSystemService* sync_service,
+                    Client* client,
                     scoped_ptr<TimerHelper> timer_helper,
                     int max_parallel_task);
   virtual ~SyncProcessRunner();
 
   // Subclass must implement this.
   virtual void StartSync(const SyncStatusCallback& callback) = 0;
 
   // Schedules a new sync.
   void Schedule();
   void ScheduleIfNotRunning();
 
   int64 pending_changes() const { return pending_changes_; }
 
  protected:
   void OnChangesUpdated(int64 pending_changes);
-  SyncFileSystemService* sync_service() { return sync_service_; }
+  SyncFileSystemService* GetSyncService();
 
   // Returns the current service state.  Default implementation returns
   // sync_service()->GetSyncServiceState().
   virtual SyncServiceState GetServiceState();
 
  private:
   void Finished(const base::TimeTicks& start_time, SyncStatusCode status);
   void Run();
   void ScheduleInternal(int64 delay);
 
   std::string name_;
-  SyncFileSystemService* sync_service_;
+  Client* client_;
   int max_parallel_task_;
   int running_tasks_;
   scoped_ptr<TimerHelper> timer_helper_;
   base::TimeTicks last_scheduled_;
   int64 current_delay_;
   int64 last_delay_;
   int64 pending_changes_;
   base::WeakPtrFactory<SyncProcessRunner> factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncProcessRunner);
 };
 
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_SYNC_PROCESS_RUNNER_H_