Move LazyBackgroundTaskQueueTest into extensions_unittests

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 11 matching lines @@
 // };
 ExtensionsTest::ExtensionsTest()
     : content_client_(new content::ContentClient),
       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::SetBrowserClientForTesting(content_browser_client_.get());
   ExtensionsBrowserClient::Set(extensions_browser_client_.get());
+}
 
+ExtensionsTest::~ExtensionsTest() {
+  ExtensionsBrowserClient::Set(NULL);
+  content::SetBrowserClientForTesting(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());
 }
 
-ExtensionsTest::~ExtensionsTest() {
+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());
-
-  ExtensionsBrowserClient::Set(NULL);
-  content::SetBrowserClientForTesting(NULL);
-  content::SetContentClient(NULL);
 }
 
 }  // namespace extensions