Refactor code that defers extension background page loading

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"
 
 using content::BrowserContext;
 
 namespace extensions {
 
 TestExtensionsBrowserClient::TestExtensionsBrowserClient(
     BrowserContext* main_context)
-    : main_context_(main_context), incognito_context_(NULL) {
+    : main_context_(main_context),
+      incognito_context_(NULL),
+      defer_loading_background_hosts_(false) {
   DCHECK(main_context_);
   DCHECK(!main_context_->IsOffTheRecord());
 }
 
 TestExtensionsBrowserClient::~TestExtensionsBrowserClient() {}
 
 void TestExtensionsBrowserClient::SetIncognitoContext(BrowserContext* context) {
   // If a context is provided it must be off-the-record.
   DCHECK(!context || context->IsOffTheRecord());
   incognito_context_ = context;
@@ skipping 82 matching lines @@
     BrowserContext* context) {
   return NULL;
 }
 
 void TestExtensionsBrowserClient::GetEarlyExtensionPrefsObservers(
     content::BrowserContext* context,
     std::vector<ExtensionPrefsObserver*>* observers) const {}
 
 bool TestExtensionsBrowserClient::DeferLoadingBackgroundHosts(
     BrowserContext* context) const {
-  return false;
+  return defer_loading_background_hosts_;
 }
 
 bool TestExtensionsBrowserClient::IsBackgroundPageAllowed(
     BrowserContext* context) const {
   return true;
 }
 
 scoped_ptr<ExtensionHostDelegate>
 TestExtensionsBrowserClient::CreateExtensionHostDelegate() {
   return scoped_ptr<ExtensionHostDelegate>();
 }
 
 bool TestExtensionsBrowserClient::DidVersionUpdate(BrowserContext* context) {
   return false;
 }
 
 scoped_ptr<AppSorting> TestExtensionsBrowserClient::CreateAppSorting() {
   return scoped_ptr<AppSorting>();
 }
 
 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;
 }
 
 }  // namespace extensions