Use ScopedTaskEnvironment instead of MessageLoopForUI in content tests.

content/renderer/media_capture_from_element/html_video_element_capturer_source_unittest.cc

 // Copyright 2015 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/renderer/media_capture_from_element/html_video_element_capturer_source.h"
 #include "base/bind.h"
 #include "base/memory/weak_ptr.h"
 #include "base/run_loop.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread_task_runner_handle.h"
-#include "content/renderer/media_capture_from_element/html_video_element_capturer_source.h"
 #include "media/base/limits.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/WebKit/public/platform/WebMediaPlayer.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 
 using ::testing::_;
 using ::testing::InSequence;
 using ::testing::Mock;
 using ::testing::SaveArg;
@@ skipping 56 matching lines @@
     // We could fill in |canvas| with a meaningful pattern in ARGB and verify
     // that is correctly captured (as I420) by HTMLVideoElementCapturerSource
     // but I don't think that'll be easy/useful/robust, so just let go here.
     return;
   }
 };
 
 class HTMLVideoElementCapturerSourceTest : public testing::Test {
  public:
   HTMLVideoElementCapturerSourceTest()
-      : web_media_player_(new MockWebMediaPlayer()),
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI),
+        web_media_player_(new MockWebMediaPlayer()),
         html_video_capturer_(new HtmlVideoElementCapturerSource(
             web_media_player_->AsWeakPtr(),
             base::ThreadTaskRunnerHandle::Get())) {}
 
   // Necessary callbacks and MOCK_METHODS for them.
   MOCK_METHOD2(DoOnDeliverFrame,
                void(const scoped_refptr<media::VideoFrame>&, base::TimeTicks));
   void OnDeliverFrame(const scoped_refptr<media::VideoFrame>& video_frame,
                     base::TimeTicks estimated_capture_time) {
     DoOnDeliverFrame(video_frame, estimated_capture_time);
   }
 
   MOCK_METHOD1(DoOnVideoCaptureDeviceFormats,
                void(const media::VideoCaptureFormats&));
   void OnVideoCaptureDeviceFormats(const media::VideoCaptureFormats& formats) {
     DoOnVideoCaptureDeviceFormats(formats);
   }
 
   MOCK_METHOD1(DoOnRunning, void(bool));
   void OnRunning(bool state) { DoOnRunning(state); }
 
  protected:
   // We need some kind of message loop to allow |html_video_capturer_| to
   // schedule capture events.
-  const base::MessageLoopForUI message_loop_;
+  const base::test::ScopedTaskEnvironment scoped_task_environment_;
 
   std::unique_ptr<MockWebMediaPlayer> web_media_player_;
   std::unique_ptr<HtmlVideoElementCapturerSource> html_video_capturer_;
 };
 
 // Constructs and destructs all objects, in particular |html_video_capturer_|
 // and its inner object(s). This is a non trivial sequence.
 TEST_F(HTMLVideoElementCapturerSourceTest, ConstructAndDestruct) {}
 
 // Checks that the usual sequence of GetCurrentSupportedFormats() ->
@@ skipping 37 matching lines @@
       base::Bind(&HTMLVideoElementCapturerSourceTest::OnRunning,
                  base::Unretained(this)));
 
   run_loop.Run();
 
   html_video_capturer_->StopCapture();
   Mock::VerifyAndClearExpectations(this);
 }
 
 }  // namespace content