Use ScopedTaskEnvironment instead of MessageLoopForUI in content tests.

content/renderer/media_recorder/media_recorder_handler_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 <stddef.h>
 
 #include <string>
 
 #include "base/macros.h"
 #include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/time/time.h"
 #include "content/child/child_process.h"
 #include "content/renderer/media/mock_media_stream_registry.h"
 #include "content/renderer/media_recorder/media_recorder_handler.h"
 #include "media/audio/simple_sources.h"
 #include "media/base/audio_bus.h"
 #include "media/base/video_frame.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/WebKit/public/platform/WebMediaRecorderHandlerClient.h"
@@ skipping 43 matching lines @@
     {true, false, "video/webm", "vp9", true},
 #if BUILDFLAG(RTC_USE_H264)
     {true, false, "video/webm", "h264", false},
 #endif
     {false, true, "video/webm", "vp8", true}};
 
 class MediaRecorderHandlerTest : public TestWithParam<MediaRecorderTestParams>,
                                  public blink::WebMediaRecorderHandlerClient {
  public:
   MediaRecorderHandlerTest()
-      : media_recorder_handler_(new MediaRecorderHandler()),
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI),
+        media_recorder_handler_(new MediaRecorderHandler()),
         audio_source_(kTestAudioChannels,
                       440 /* freq */,
                       kTestAudioSampleRate) {
     EXPECT_FALSE(media_recorder_handler_->recording_);
 
     registry_.Init(kTestStreamUrl);
   }
 
   ~MediaRecorderHandlerTest() {
     registry_.reset();
@@ skipping 39 matching lines @@
     std::unique_ptr<media::AudioBus> bus(media::AudioBus::Create(
         kTestAudioChannels,
         kTestAudioSampleRate * kTestAudioBufferDurationMs / 1000));
     audio_source_.OnMoreData(base::TimeDelta(), base::TimeTicks::Now(), 0,
                              bus.get());
     return bus;
   }
 
   // A ChildProcess and a MessageLoopForUI are both needed to fool the Tracks
   // and Sources in |registry_| into believing they are on the right threads.
-  const base::MessageLoopForUI message_loop_;
+  const base::test::ScopedTaskEnvironment scoped_task_environment_;
   const ChildProcess child_process_;
   MockMediaStreamRegistry registry_;
 
   // The Class under test. Needs to be scoped_ptr to force its destruction.
   std::unique_ptr<MediaRecorderHandler> media_recorder_handler_;
 
   // For generating test AudioBuses
   media::SineWaveAudioSource audio_source_;
 
  private:
@@ skipping 269 matching lines @@
     run_loop.Run();
   }
 
 
   // Expect a last call on destruction, with size 0 and |lastInSlice| true.
   EXPECT_CALL(*this, WriteData(nullptr, 0, true, _)).Times(1);
   media_recorder_handler_.reset();
 }
 
 }  // namespace content