Makes GetComponentExtensionResourceManager() thread-safe.

extensions/browser/test_extensions_browser_client.cc

 // Copyright 2014 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.
 
 #include "extensions/browser/test_extensions_browser_client.h"
 
 #include "content/public/browser/browser_context.h"
 #include "extensions/browser/app_sorting.h"
 #include "extensions/browser/extension_host_delegate.h"
 #include "extensions/browser/test_runtime_api_delegate.h"
@@ skipping 141 matching lines @@
 
 void TestExtensionsBrowserClient::RegisterExtensionFunctions(
     ExtensionFunctionRegistry* registry) const {}
 
 scoped_ptr<RuntimeAPIDelegate>
 TestExtensionsBrowserClient::CreateRuntimeAPIDelegate(
     content::BrowserContext* context) const {
   return scoped_ptr<RuntimeAPIDelegate>(new TestRuntimeAPIDelegate());
 }
 
-ComponentExtensionResourceManager*
+const ComponentExtensionResourceManager*
 TestExtensionsBrowserClient::GetComponentExtensionResourceManager() {
   return NULL;
 }
 
 void TestExtensionsBrowserClient::BroadcastEventToRenderers(
     const std::string& event_name,
     scoped_ptr<base::ListValue> args) {
 }
 
 net::NetLog* TestExtensionsBrowserClient::GetNetLog() {
   return NULL;
 }
 
 ExtensionCache* TestExtensionsBrowserClient::GetExtensionCache() {
   return extension_cache_.get();
 }
 
 bool TestExtensionsBrowserClient::IsBackgroundUpdateAllowed() {
   return true;
 }
 
 bool TestExtensionsBrowserClient::IsMinBrowserVersionSupported(
     const std::string& min_version) {
   return true;
 }
 
 }  // namespace extensions