Makes GetComponentExtensionResourceManager() thread-safe.

extensions/browser/extensions_browser_client.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 EXTENSIONS_BROWSER_EXTENSIONS_BROWSER_CLIENT_H_
 #define EXTENSIONS_BROWSER_EXTENSIONS_BROWSER_CLIENT_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 159 matching lines @@
       ExtensionFunctionRegistry* registry) const = 0;
 
   // Creates a RuntimeAPIDelegate responsible for handling extensions
   // management-related events such as update and installation on behalf of the
   // core runtime API implementation.
   virtual scoped_ptr<RuntimeAPIDelegate> CreateRuntimeAPIDelegate(
       content::BrowserContext* context) const = 0;
 
   // Returns the manager of resource bundles used in extensions. Returns NULL if
   // the manager doesn't exist.
-  virtual ComponentExtensionResourceManager*
+  virtual const ComponentExtensionResourceManager*
   GetComponentExtensionResourceManager() = 0;
 
   // Propagate a event to all the renderers in every browser context. The
   // implementation must be safe to call from any thread.
   virtual void BroadcastEventToRenderers(const std::string& event_name,
                                          scoped_ptr<base::ListValue> args) = 0;
 
   // Returns the embedder's net::NetLog.
   virtual net::NetLog* GetNetLog() = 0;
 
@@ skipping 12 matching lines @@
   // Returns the single instance of |this|.
   static ExtensionsBrowserClient* Get();
 
   // Initialize the single instance.
   static void Set(ExtensionsBrowserClient* client);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_EXTENSIONS_BROWSER_CLIENT_H_