Use ScopedTaskEnvironment instead of MessageLoopForUI in chrome tests.

chrome/browser/extensions/extension_user_script_loader_unittest.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/extension_user_script_loader.h"
 
 #include <stddef.h>
 
 #include <set>
 #include <string>
 
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/location.h"
 #include "base/memory/ptr_util.h"
+#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_util.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/test/base/testing_profile.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/notification_service.h"
-#include "content/public/test/test_browser_thread.h"
+#include "content/public/test/test_browser_thread_bundle.h"
 #include "extensions/common/host_id.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-using content::BrowserThread;
 using extensions::URLPatternSet;
 
 namespace {
 
 static void AddPattern(URLPatternSet* extent, const std::string& pattern) {
   int schemes = URLPattern::SCHEME_ALL;
   extent->AddPattern(URLPattern(schemes, pattern));
 }
 }
 
 namespace extensions {
 
 // Test bringing up a script loader on a specific directory, putting a script
 // in there, etc.
 
 class ExtensionUserScriptLoaderTest : public testing::Test,
                                       public content::NotificationObserver {
  public:
-  ExtensionUserScriptLoaderTest() : shared_memory_(NULL) {}
+  ExtensionUserScriptLoaderTest()
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI),
+        shared_memory_(NULL) {}
 
   void SetUp() override {
     ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
 
     // Register for all user script notifications.
     registrar_.Add(this,
                    extensions::NOTIFICATION_USER_SCRIPTS_UPDATED,
                    content::NotificationService::AllSources());
-
-    // ExtensionUserScriptLoader posts tasks to the file thread so make the

[sky, 2017/04/27 22:17:46]

Is this the same with ScopedTaskEvironment?

[fdoray, 2017/05/01 17:44:59]

I added a TestBrowserThreadBundle instead of a ScopedTaskEnvironment to this
test. It runs all the existing types of BrowserThreads on the main thread
(equivalent to instantiating multiple content::TestBrowserThread).

[sky, 2017/05/01 18:07:07]

I'm not sure that is the same thing. Could you get a local owner to make sure
that is appropriate.

[fdoray, 2017/05/01 18:15:47]

I'll do this part in a separate CL.

-    // current thread look like one.
-    file_thread_.reset(new content::TestBrowserThread(
-        BrowserThread::FILE, base::MessageLoop::current()));
-    ui_thread_.reset(new content::TestBrowserThread(
-        BrowserThread::UI, base::MessageLoop::current()));
-  }
-
-  void TearDown() override {
-    file_thread_.reset();
-    ui_thread_.reset();
   }
 
   void Observe(int type,
                const content::NotificationSource& source,
                const content::NotificationDetails& details) override {
     DCHECK(type == extensions::NOTIFICATION_USER_SCRIPTS_UPDATED);
 
     shared_memory_ = content::Details<base::SharedMemory>(details).ptr();
-    if (base::MessageLoop::current() == &message_loop_)
+    if (main_thread_task_runner_->RunsTasksOnCurrentThread())
       base::MessageLoop::current()->QuitWhenIdle();
   }
 
+  content::TestBrowserThreadBundle test_browser_thread_bundle_;
+
+  const scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_ =
+      base::ThreadTaskRunnerHandle::Get();
+
   // Directory containing user scripts.
   base::ScopedTempDir temp_dir_;
 
   content::NotificationRegistrar registrar_;
 
-  // MessageLoop used in tests.
-  base::MessageLoopForUI message_loop_;
-
-  std::unique_ptr<content::TestBrowserThread> file_thread_;
-  std::unique_ptr<content::TestBrowserThread> ui_thread_;
-
   // Updated to the script shared memory when we get notified.
   base::SharedMemory* shared_memory_;
 };
 
 // Test that we get notified even when there are no scripts.
 TEST_F(ExtensionUserScriptLoaderTest, NoScripts) {
   TestingProfile profile;
   ExtensionUserScriptLoader loader(
       &profile,
       HostID(),
@@ skipping 170 matching lines @@
       &profile,
       HostID(),
       true /* listen_for_extension_system_loaded */);
   loader.LoadScriptsForTest(&user_scripts);
 
   EXPECT_EQ(content,
             user_scripts[0]->js_scripts()[0]->GetContent().as_string());
 }
 
 }  // namespace extensions