Make MockExtensionSystemFactory available in all ExtensionsTests.

extensions/browser/extensions_test.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/extensions_test.h"
 
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/common/content_client.h"
 #include "content/public/test/test_browser_context.h"
@@ skipping 14 matching lines @@
     : content_client_(new content::ContentClient),
       content_utility_client_(new TestContentUtilityClient),
       content_browser_client_(new content::ContentBrowserClient),
       browser_context_(new content::TestBrowserContext),
       extensions_browser_client_(
           new TestExtensionsBrowserClient(browser_context_.get())) {
   content::SetContentClient(content_client_.get());
   content::SetUtilityClientForTesting(content_utility_client_.get());
   content::SetBrowserClientForTesting(content_browser_client_.get());
   ExtensionsBrowserClient::Set(extensions_browser_client_.get());
+  extensions_browser_client_->set_extension_system_factory(
+      &extension_system_factory_);
 }
 
 ExtensionsTest::~ExtensionsTest() {
   ExtensionsBrowserClient::Set(NULL);
   content::SetBrowserClientForTesting(NULL);
   content::SetUtilityClientForTesting(NULL);
   content::SetContentClient(NULL);
 }
 
 void ExtensionsTest::SetUp() {
   // Crashing here? Don't use this class in Chrome's unit_tests. See header.
   BrowserContextDependencyManager::GetInstance()
       ->CreateBrowserContextServicesForTest(browser_context_.get());
 }
 
 void ExtensionsTest::TearDown() {
   // Allows individual tests to have BrowserContextKeyedServiceFactory objects
   // as member variables instead of singletons. The individual services will be
   // cleaned up before the factories are destroyed.
   BrowserContextDependencyManager::GetInstance()->DestroyBrowserContextServices(
       browser_context_.get());
 }
 
 }  // namespace extensions