Use ScopedTaskEnvironment instead of MessageLoopForUI in ui/aura/test/.

content/browser/media/capture/desktop_capture_device_aura_unittest.cc

 // Copyright 2013 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 "content/browser/media/capture/desktop_capture_device_aura.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <utility>
 
@@ skipping 93 matching lines @@
 
  protected:
   void SetUp() override {
     // The ContextFactory must exist before any Compositors are created.
 
     bool enable_pixel_output = false;
     ui::ContextFactory* context_factory = nullptr;
     ui::ContextFactoryPrivate* context_factory_private = nullptr;
     ui::InitializeContextFactoryForTests(enable_pixel_output, &context_factory,
                                          &context_factory_private);
-    helper_.reset(
-        new aura::test::AuraTestHelper(base::MessageLoopForUI::current()));
+    helper_.reset(new aura::test::AuraTestHelper());
     helper_->SetUp(context_factory, context_factory_private);
     new wm::DefaultActivationClient(helper_->root_window());
     // We need a window to cover desktop area so that DesktopCaptureDeviceAura
     // can use gfx::NativeWindow::GetWindowAtScreenPoint() to locate the
     // root window associated with the primary display.
     gfx::Rect desktop_bounds = root_window()->bounds();
     window_delegate_.reset(new aura::test::TestWindowDelegate());
     desktop_window_.reset(new aura::Window(window_delegate_.get()));
     desktop_window_->Init(ui::LAYER_TEXTURED);
     desktop_window_->SetBounds(desktop_bounds);
@@ skipping 38 matching lines @@
   media::VideoCaptureParams capture_params;
   capture_params.requested_format.frame_size.SetSize(640, 480);
   capture_params.requested_format.frame_rate = kFrameRate;
   capture_params.requested_format.pixel_format = media::PIXEL_FORMAT_I420;
   capture_device->AllocateAndStart(capture_params, std::move(client));
   capture_device->StopAndDeAllocate();
 }
 
 }  // namespace
 }  // namespace content