Split up SyncEngineEventListener callbacks

sync/sessions/sync_session_context.h

 // Copyright 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.
 
 // SyncSessionContext encapsulates the contextual information and engine
 // components specific to a SyncSession.  Unlike the SyncSession, the context
 // can be reused across several sync cycles.
 //
 // The context does not take ownership of its pointer members.  It's up to
 // the surrounding classes to ensure those members remain valid while the
@@ skipping 76 matching lines @@
     DCHECK(account_name_.empty());
     account_name_ = name;
   }
   const std::string& account_name() const { return account_name_; }
 
   void set_max_commit_batch_size(int batch_size) {
     max_commit_batch_size_ = batch_size;
   }
   int32 max_commit_batch_size() const { return max_commit_batch_size_; }
 
-  void NotifyListeners(const SyncEngineEvent& event) {
-    FOR_EACH_OBSERVER(SyncEngineEventListener, listeners_,
-                      OnSyncEngineEvent(event));
+  ObserverList<SyncEngineEventListener>* listeners() {
+    return &listeners_;
   }
 
   TrafficRecorder* traffic_recorder() {
     return traffic_recorder_;
   }
 
   bool keystore_encryption_enabled() const {
     return keystore_encryption_enabled_;
   }
 
@@ skipping 82 matching lines @@
   // enable the pre-commit update avoidance experiment described above.
   const bool client_enabled_pre_commit_update_avoidance_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncSessionContext);
 };
 
 }  // namespace sessions
 }  // namespace syncer
 
 #endif  // SYNC_SESSIONS_SYNC_SESSION_CONTEXT_H_