Move LazyBackgroundTaskQueueTest into extensions_unittests

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 130 matching lines @@
 
 bool TestExtensionsBrowserClient::IsRunningInForcedAppMode() { return false; }
 
 ApiActivityMonitor* TestExtensionsBrowserClient::GetApiActivityMonitor(
     BrowserContext* context) {
   return NULL;
 }
 
 ExtensionSystemProvider*
 TestExtensionsBrowserClient::GetExtensionSystemFactory() {
-  // Tests requiring an extension system should override this function.
-  NOTREACHED();
-  return NULL;
+  DCHECK(extension_system_factory_);
+  return extension_system_factory_;
 }
 
 void TestExtensionsBrowserClient::RegisterExtensionFunctions(
     ExtensionFunctionRegistry* registry) const {}
 
 scoped_ptr<RuntimeAPIDelegate>
 TestExtensionsBrowserClient::CreateRuntimeAPIDelegate(
     content::BrowserContext* context) const {
   return scoped_ptr<RuntimeAPIDelegate>(new TestRuntimeAPIDelegate());
 }
 
 ComponentExtensionResourceManager*
 TestExtensionsBrowserClient::GetComponentExtensionResourceManager() {
   return NULL;
 }
 
 net::NetLog* TestExtensionsBrowserClient::GetNetLog() {
   return NULL;
 }
 
 }  // namespace extensions