Use ScopedTaskEnvironment instead of MessageLoopForUI in ViewsTestBase.

ui/views/controls/webview/webview_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 "ui/views/controls/webview/webview.h"
 
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
-#include "base/message_loop/message_loop.h"
-#include "base/test/scoped_task_scheduler.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/test/test_browser_context.h"
-#include "content/public/test/test_browser_thread.h"
+#include "content/public/test/test_browser_thread_bundle.h"
 #include "content/public/test/web_contents_tester.h"
 #include "content/test/test_content_browser_client.h"
 #include "ui/events/event.h"
 #include "ui/events/event_utils.h"
 #include "ui/views/controls/native/native_view_host.h"
 #include "ui/views/test/test_views_delegate.h"
 #include "ui/views/test/widget_test.h"
 
 #if defined(USE_AURA)
 #include "ui/aura/window.h"
@@ skipping 96 matching lines @@
   bool is_fullscreened_;
 
   DISALLOW_COPY_AND_ASSIGN(WebViewTestWebContentsDelegate);
 };
 
 }  // namespace
 
 // Provides functionality to test a WebView.
 class WebViewUnitTest : public views::test::WidgetTest {
  public:
-  WebViewUnitTest()
-      : ui_thread_(content::BrowserThread::UI, base::MessageLoop::current()),
-        scoped_task_scheduler_(base::MessageLoop::current()),
-        file_blocking_thread_(content::BrowserThread::FILE_USER_BLOCKING,
-                              base::MessageLoop::current()),
-        io_thread_(content::BrowserThread::IO, base::MessageLoop::current()),
-        top_level_widget_(nullptr) {}
+  WebViewUnitTest() = default;
 
   ~WebViewUnitTest() override {}
 
   void SetUp() override {
     set_views_delegate(base::WrapUnique(new WebViewTestViewsDelegate));
     browser_context_.reset(new content::TestBrowserContext);
     WidgetTest::SetUp();
     // Set the test content browser client to avoid pulling in needless
     // dependencies from content.
     SetBrowserClientForTesting(&test_browser_client_);
@@ skipping 26 matching lines @@
   Widget* top_level_widget() const { return top_level_widget_; }
   WebView* web_view() const { return web_view_; }
   NativeViewHost* holder() const { return web_view_->holder_; }
 
   std::unique_ptr<content::WebContents> CreateWebContents() const {
     return base::WrapUnique(content::WebContents::Create(
         content::WebContents::CreateParams(browser_context_.get())));
   }
 
  private:
-  content::TestBrowserThread ui_thread_;
-  base::test::ScopedTaskScheduler scoped_task_scheduler_;
-  content::TestBrowserThread file_blocking_thread_;
-  content::TestBrowserThread io_thread_;
+  content::TestBrowserThreadBundle test_browser_thread_bundle_;
   std::unique_ptr<content::TestBrowserContext> browser_context_;
   content::TestContentBrowserClient test_browser_client_;
 
-  Widget* top_level_widget_;
-  WebView* web_view_;
+  Widget* top_level_widget_ = nullptr;
+  WebView* web_view_ = nullptr;
 
   DISALLOW_COPY_AND_ASSIGN(WebViewUnitTest);
 };
 
 // Tests that attaching and detaching a WebContents to a WebView makes the
 // WebContents visible and hidden respectively.
 TEST_F(WebViewUnitTest, TestWebViewAttachDetachWebContents) {
   // Case 1: Create a new WebContents and set it in the webview via
   // SetWebContents. This should make the WebContents visible.
   const std::unique_ptr<content::WebContents> web_contents1(
@@ skipping 273 matching lines @@
 
   // Remove WebView from views hierarchy. NativeView should be detached
   // from Widget.
   contents_view->RemoveChildView(webview.get());
   // Destroy WebView. NativeView should be detached secondary.
   // There should be no crash.
   webview.reset();
 }
 
 }  // namespace views