Add DCHECK to ensure IndexedDBDispatcher doesn't get re-created.

content/common/indexed_db/indexed_db_dispatcher.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 CONTENT_COMMON_INDEXED_DB_INDEXED_DB_DISPATCHER_H_
 #define CONTENT_COMMON_INDEXED_DB_INDEXED_DB_DISPATCHER_H_
 #pragma once
 
 #include <map>
 #include <vector>
@@ skipping 31 matching lines @@
 class SerializedScriptValue;
 }
 
 CONTENT_EXPORT extern const size_t kMaxIDBValueSizeInBytes;
 
 // Handle the indexed db related communication for this context thread - the
 // main thread and each worker thread have their own copies.
 class CONTENT_EXPORT IndexedDBDispatcher
     : public webkit_glue::WorkerTaskRunner::Observer {
  public:
+  // Constructor made public to allow RenderThreadImpl to own a copy without
+  // failing a NOTREACHED in ThreadSpecificInstance in tests that instantiate
+  // two copies of RenderThreadImpl on the same thread.  Everyone else probably
+  // wants to use ThreadSpecificInstance().
+  IndexedDBDispatcher();
   virtual ~IndexedDBDispatcher();
   static IndexedDBDispatcher* ThreadSpecificInstance();
 
   // webkit_glue::WorkerTaskRunner::Observer implementation.
   virtual void OnWorkerRunLoopStopped() OVERRIDE;
 
   void OnMessageReceived(const IPC::Message& msg);
   static bool Send(IPC::Message* msg);
 
   void RequestIDBFactoryGetDatabaseNames(
@@ skipping 140 matching lines @@
       WebKit::WebIDBTransactionCallbacks* callbacks,
       int32 id);
 
   void CursorDestroyed(int32 cursor_id);
 
   static int32 TransactionId(const WebKit::WebIDBTransaction& transaction);
 
  private:
   FRIEND_TEST_ALL_PREFIXES(IndexedDBDispatcherTest, ValueSizeTest);
 
-  IndexedDBDispatcher();
   // IDBCallback message handlers.
   void OnSuccessNull(int32 response_id);
   void OnSuccessIDBDatabase(int32 thread_id,
                             int32 response_id,
                             int32 object_id);
   void OnSuccessIndexedDBKey(int32 thread_id,
                              int32 response_id,
                              const IndexedDBKey& key);
   void OnSuccessIDBTransaction(int32 thread_id,
                                int32 response_id,
@@ skipping 33 matching lines @@
   IDMap<WebKit::WebIDBDatabaseCallbacks, IDMapOwnPointer>
       pending_database_callbacks_;
 
   // Map from cursor id to RendererWebIDBCursorImpl.
   std::map<int32, RendererWebIDBCursorImpl*> cursors_;
 
   DISALLOW_COPY_AND_ASSIGN(IndexedDBDispatcher);
 };
 
 #endif  // CONTENT_COMMON_INDEXED_DB_INDEXED_DB_DISPATCHER_H_