[Sync] Rework SharedValue<T> into Immutable<T>

chrome/browser/sync/js/js_transaction_observer.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_JS_JS_TRANSACTION_OBSERVER_H_
 #define CHROME_BROWSER_SYNC_JS_JS_TRANSACTION_OBSERVER_H_
 #pragma once
 
 #include <string>
 
@@ skipping 21 matching lines @@
 
   void SetJsEventHandler(const WeakHandle<JsEventHandler>& event_handler);
 
   // syncable::TransactionObserver implementation.
   virtual void OnTransactionStart(
       const tracked_objects::Location& location,
       const syncable::WriterTag& writer) OVERRIDE;
   virtual void OnTransactionMutate(
       const tracked_objects::Location& location,
       const syncable::WriterTag& writer,
-      const syncable::SharedEntryKernelMutationMap& mutations,
+      const syncable::ImmutableEntryKernelMutationMap& mutations,
       const syncable::ModelTypeBitSet& models_with_changes) OVERRIDE;
   virtual void OnTransactionEnd(
       const tracked_objects::Location& location,
       const syncable::WriterTag& writer) OVERRIDE;
 
  private:
   base::NonThreadSafe non_thread_safe_;
   WeakHandle<JsEventHandler> event_handler_;
 
   void HandleJsEvent(
     const tracked_objects::Location& from_here,
     const std::string& name, const JsEventDetails& details);
 
   DISALLOW_COPY_AND_ASSIGN(JsTransactionObserver);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_JS_JS_TRANSACTION_OBSERVER_H_