Unit test for WebMediaPlayerMS

content/renderer/media/webmediaplayer_ms_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 "base/strings/string_number_conversions.h"
+#include "base/strings/string_split.h"
+#include "cc/layers/video_frame_provider.h"
+#include "content/public/renderer/media_stream_renderer_factory.h"
+#include "content/renderer/media/webmediaplayer_ms.h"
+#include "content/renderer/media/webmediaplayer_ms_compositor.h"
+#include "content/renderer/render_frame_impl.h"
+#include "media/base/test_helpers.h"
+#include "media/base/video_frame.h"
+#include "third_party/WebKit/public/platform/WebMediaPlayer.h"
+#include "third_party/WebKit/public/platform/WebMediaPlayerClient.h"
+
+namespace content {
+
+class WebMediaPlayerMSTest;

[mcasas, 2015/11/04 22:20:31]

Why this forward declaration?

[qiangchen, 2015/11/06 19:14:58]

Done.

+
+class MockCB {
+ public:
+  MOCK_METHOD0(StartRendering, void());
+  MOCK_METHOD0(StopRendering, void());
+
+  MOCK_METHOD1(SetWebLayer, void(bool));
+  MOCK_METHOD1(NetworkStateChanged, void(blink::WebMediaPlayer::NetworkState));
+  MOCK_METHOD1(ReadyStateChanged, void(blink::WebMediaPlayer::ReadyState));
+  void VerifyAndClearExpectations() {
+    // Note: the raw value of "this" could be different from &mock_cb_.
+    // So this is not equivalent with calling
+    // VerifyAndClearExpectations(&mock_cb_) outside.
+    testing::Mock::VerifyAndClearExpectations(this);
+  }
+};
+
+struct TestFrame {
+  enum TestFrameType {
+    NORMAL_FRAME,
+    BROKEN_FRAME,
+    TEST_BRAKE  // Signal to pause message loop.
+  };
+  TestFrame(TestFrameType input_category,
+            const scoped_refptr<media::VideoFrame>& input_frame)
+      : category(input_category), frame(input_frame) {}
+
+  TestFrameType category;
+  scoped_refptr<media::VideoFrame> frame;
+};
+
+class ReusableMessageLoopEvent {

[mcasas, 2015/11/04 22:20:31]

How's this class different from media::WaitableMessageLoopEvent?

IOW, private inheritance == encapsulation of a single class
is somehow seldom seen. I would be less surprised if you
would do a 

class ReusableMessageLoopEvent : public media::WaitableMessageLoopEvent

and override RunAndWait()/RunAndWaitForStatus() so 
the the parent's class |run_loop_| is reused. 

[qiangchen, 2015/11/06 19:14:58]

The main reason I made this class is to deal with the following situation if we
do not define the ReusableEvent: 
Say Class A has an instance of WaitableMessageLoopEvent, and Class B holds a
pointer to that WaitableMessageLoopEvent.
Say in A::method(), it calls WaitableMessageLoopEvent::RunAndWait(), and then it
replaces the WaitableMessageLoopEvent with a brand new one for further testing
work. 
The problem is that Class B now is holding a pointer to the old
WaitableMessageLoopEvent which is useless any more.

Inheritance and function overriding has a difficulty for now: the functions are
not virtual. If we want to do that way, we have to modify test_helpers.h and .cc
files.

+ public:
+  ReusableMessageLoopEvent() : event_(new media::WaitableMessageLoopEvent()) {}
+
+  base::Closure GetClosure() { return event_->GetClosure(); }
+
+  media::PipelineStatusCB GetPipelineStatusCB() {
+    return event_->GetPipelineStatusCB();
+  }
+
+  void RunAndWait() {
+    event_->RunAndWait();
+    event_.reset(new media::WaitableMessageLoopEvent());
+  }
+
+  void RunAndWaitForStatus(media::PipelineStatus expected) {
+    event_->RunAndWaitForStatus(expected);
+    event_.reset(new media::WaitableMessageLoopEvent());
+  }
+
+ private:
+  scoped_ptr<media::WaitableMessageLoopEvent> event_;
+};
+
+// The class mainly used to inject VideoFrames into WebMediaPlayerMS.
+class MockVideoFrameProvider : public VideoFrameProvider {
+ public:
+  MockVideoFrameProvider(base::MessageLoop* message_loop,
+                         ReusableMessageLoopEvent* message_loop_controller,
+                         const base::Closure& error_cb,
+                         const VideoFrameProvider::RepaintCB& repaint_cb)
+      : started_(false),
+        message_loop_(message_loop),
+        message_loop_controller_(message_loop_controller),
+        error_cb_(error_cb),
+        repaint_cb_(repaint_cb),
+        delay_(base::TimeDelta::FromSecondsD(1.0 / 30.0)) {}
+
+  // Implementation of VideoFrameProvider
+  void Start() override {
+    started_ = true;

[mcasas, 2015/11/04 22:20:31]

Do not inline method bodies if the body is >= 2 lines.
This is a flexible rule, if one of the 2 lines is a DCHECK(),
use your common sense.

[qiangchen, 2015/11/06 19:14:58]

Done.

+    paused_ = false;
+    message_loop_->PostTask(FROM_HERE,
+                            base::Bind(&MockVideoFrameProvider::InjectFrame,
+                                       base::Unretained(this)));
+  }
+
+  void Stop() override {
+    started_ = false;
+    frames_.clear();
+  }
+
+  void Play() override {
+    CHECK(started_);
+    paused_ = false;
+  }
+
+  void Pause() override {
+    CHECK(started_);
+    paused_ = true;
+  }
+
+  // Methods for test use
+  void PrepareFrame(TestFrame::TestFrameType category,
+                    const scoped_refptr<media::VideoFrame>& frame) {
+    frames_.push_back(TestFrame(category, frame));
+  }
+
+  void QueueFrames(const std::vector<int>& input) {
+    for (const int token : input) {
+      if (token == -1) {

[mcasas, 2015/11/04 22:20:31]

please add anonymous enums for -1 and -2,

enum {
  FRAME_THAT_I_LIKE_A_LOT = -2,  // I like this frame.
  FRAME_I_DONT_WANT_TO_SEE = -1,  // I really dislike this one.
...
};

[qiangchen, 2015/11/06 19:14:57]

Done. Just pull the TestFrameType out to be an anonymous enum.

+        PrepareFrame(TestFrame::TestFrameType::BROKEN_FRAME, nullptr);
+        continue;
+      }
+
+      if (token == -2) {
+        PrepareFrame(TestFrame::TestFrameType::TEST_BRAKE, nullptr);
+        continue;
+      }
+
+      if (token >= 0) {
+        gfx::Size natural_size = media::TestVideoConfig::NormalCodedSize();
+        auto frame = media::VideoFrame::CreateFrame(
+            media::PIXEL_FORMAT_YV12, natural_size, gfx::Rect(natural_size),
+            natural_size, base::TimeDelta::FromMilliseconds(token));
+
+        frame->metadata()->SetTimeTicks(
+            media::VideoFrameMetadata::Key::REFERENCE_TIME,
+            base::TimeTicks::Now() + base::TimeDelta::FromMilliseconds(token));
+
+        PrepareFrame(TestFrame::TestFrameType::NORMAL_FRAME, frame);
+        continue;
+      }
+
+      CHECK(false) << "Unrecognized token: " << token;
+    }
+  }
+
+  bool Started() { return started_; }
+
+  bool Paused() { return paused_; }
+
+ private:
+  ~MockVideoFrameProvider() override {}
+
+  // Main function that pushes frame into WebMediaPlayerMS
+  void InjectFrame() {

[mcasas, 2015/11/04 22:20:31]

If this is just meant to be run on |message_loop_|, could you
please add a 
DCHECK(message_loop_->BelongsToCurrentThread()); 
?

[qiangchen, 2015/11/06 19:14:58]

Done.

+    if (!started_)
+      return;
+
+    if (frames_.empty()) {
+      message_loop_controller_->GetClosure().Run();
+      return;
+    }
+
+    auto frame = frames_.front();
+    frames_.pop_front();
+
+    if (frame.category == TestFrame::TestFrameType::BROKEN_FRAME) {
+      error_cb_.Run();
+      return;
+    }
+
+    // For pause case, the provider will still let the stream continue, but
+    // not send the frames to the player. As is the same case in reality.
+    if (frame.category == TestFrame::TestFrameType::NORMAL_FRAME) {
+      if (!paused_)
+        repaint_cb_.Run(frame.frame);
+
+      size_t i = 0;
+      while (i < frames_.size() &&
+             frames_[i].category != TestFrame::TestFrameType::NORMAL_FRAME) {
+        ++i;
+      }
+
+      if (i < frames_.size()) {
+        delay_ = (frames_[i].frame->timestamp() - frame.frame->timestamp()) /
+                 (i + 1);
+      }
+    }
+
+    message_loop_->PostDelayedTask(
+        FROM_HERE, base::Bind(&MockVideoFrameProvider::InjectFrame,
+                              base::Unretained(this)),
+        delay_);
+
+    if (frame.category == TestFrame::TestFrameType::TEST_BRAKE)
+      message_loop_controller_->GetClosure().Run();
+  }
+
+  bool started_;
+  bool paused_;
+
+  base::MessageLoop* message_loop_;
+  ReusableMessageLoopEvent* message_loop_controller_;
+  base::Closure error_cb_;
+  VideoFrameProvider::RepaintCB repaint_cb_;

[mcasas, 2015/11/04 22:20:31]

I believe all these 4 members can be const.

[qiangchen, 2015/11/06 19:14:57]

Done.

+
+  std::deque<TestFrame> frames_;
+  base::TimeDelta delay_;
+};
+
+// The class is used to generate MockVideoProvider

[mcasas, 2015/11/04 22:20:31]

"... used to generate _a_ MockVideoProvider".

[qiangchen, 2015/11/06 19:14:58]

Done.

+class MockRenderFactory : public MediaStreamRendererFactory {
+ public:
+  MockRenderFactory(base::MessageLoop* message_loop,
+                    ReusableMessageLoopEvent* message_loop_controller)
+      : message_loop_(message_loop),
+        message_loop_controller_(message_loop_controller) {}
+
+  scoped_refptr<VideoFrameProvider> GetVideoFrameProvider(
+      const GURL& url,
+      const base::Closure& error_cb,
+      const VideoFrameProvider::RepaintCB& repaint_cb,
+      const scoped_refptr<base::SingleThreadTaskRunner>& media_task_runner,
+      const scoped_refptr<base::TaskRunner>& worker_task_runner,
+      media::GpuVideoAcceleratorFactories* gpu_factories) override {
+    provider_ = new MockVideoFrameProvider(
+        message_loop_, message_loop_controller_, error_cb, repaint_cb);
+
+    return provider_;
+  }
+
+  MockVideoFrameProvider* GetVideoFrameProvider() {
+    return static_cast<MockVideoFrameProvider*>(provider_.get());
+  }
+
+  scoped_refptr<MediaStreamAudioRenderer> GetAudioRenderer(
+      const GURL& url,
+      int render_frame_id,
+      const std::string& device_id,
+      const url::Origin& security_origin) override {
+    return nullptr;
+  }
+
+ private:
+  base::MessageLoop* message_loop_;

[mcasas, 2015/11/04 22:20:31]

const?

[qiangchen, 2015/11/06 19:14:58]

Done.

+  scoped_refptr<VideoFrameProvider> provider_;
+  ReusableMessageLoopEvent* message_loop_controller_;

[mcasas, 2015/11/04 22:20:31]

const?

[qiangchen, 2015/11/06 19:14:58]

Done.

+};
+
+class WebMediaPlayerMSTest : public testing::Test,
+                             public blink::WebMediaPlayerClient,
+                             public cc::VideoFrameProvider::Client {
+ public:
+  WebMediaPlayerMSTest()
+      : render_factory_(
+            new MockRenderFactory(&message_loop_, &message_loop_controller_)),
+        player_(nullptr,
+                this,
+                base::WeakPtr<RenderFrameImpl>(),
+                new media::MediaLog(),
+                scoped_ptr<MediaStreamRendererFactory>(render_factory_),
+                message_loop_.task_runner(),
+                message_loop_.task_runner(),
+                message_loop_.task_runner(),
+                nullptr,
+                blink::WebString(),
+                blink::WebSecurityOrigin()),
+        rendering_(false) {}
+  ~WebMediaPlayerMSTest() override {}
+
+  MockVideoFrameProvider* LoadAndGetFrameProvider(bool algorithm_enabled) {
+    MockVideoFrameProvider* provider = render_factory_->GetVideoFrameProvider();
+    EXPECT_EQ(nullptr, provider);
+
+    EXPECT_CALL(mock_cb_, NetworkStateChanged(
+                              blink::WebMediaPlayer::NetworkStateLoading));
+    EXPECT_CALL(mock_cb_, ReadyStateChanged(
+                              blink::WebMediaPlayer::ReadyStateHaveNothing));
+    player_.load(blink::WebMediaPlayer::LoadTypeURL, blink::WebURL(),
+                 blink::WebMediaPlayer::CORSModeUnspecified);
+    compositor_ = player_.GetCompositorForTesting();

[mcasas, 2015/11/04 22:20:31]

You don't need GetCompositorForTesting() since 
WebMediaPlayerMSTest is a friend of 
WebMediaPlayerMS, remove it.

[qiangchen, 2015/11/06 19:14:58]

Done.

+    EXPECT_NE(nullptr, compositor_);
+    compositor_->SetAlgorithmEnabledForTesting(algorithm_enabled);
+
+    provider = render_factory_->GetVideoFrameProvider();
+    EXPECT_NE(nullptr, provider);
+    EXPECT_TRUE(provider->Started());
+
+    mock_cb_.VerifyAndClearExpectations();
+    return provider;
+  }
+
+  // Implementation of WebMediaPlayerClient
+  void networkStateChanged() override {
+    blink::WebMediaPlayer::NetworkState state = player_.networkState();
+    mock_cb_.NetworkStateChanged(state);
+    if (state == blink::WebMediaPlayer::NetworkState::NetworkStateFormatError ||
+        state == blink::WebMediaPlayer::NetworkState::NetworkStateDecodeError ||
+        state ==
+            blink::WebMediaPlayer::NetworkState::NetworkStateNetworkError) {
+      message_loop_controller_.GetPipelineStatusCB().Run(
+          media::PipelineStatus::PIPELINE_ERROR_NETWORK);
+    }
+  }
+
+  void readyStateChanged() override {
+    blink::WebMediaPlayer::ReadyState state = player_.readyState();
+    mock_cb_.ReadyStateChanged(state);
+    if (state == blink::WebMediaPlayer::ReadyState::ReadyStateHaveEnoughData)
+      player_.play();
+  }
+
+  void timeChanged() override {}
+  void repaint() override {}
+  void durationChanged() override {}
+  void sizeChanged() override {}
+  void playbackStateChanged() override {}
+  void setWebLayer(blink::WebLayer* layer) override {
+    if (layer) {
+      compositor_->SetVideoFrameProviderClient(this);
+    }

[mcasas, 2015/11/04 22:20:30]

No need for {} [1]
" In general, curly braces are not required for single-line statements "

[1] https://google.github.io/styleguide/cppguide.html#Conditionals

[qiangchen, 2015/11/06 19:14:58]

Done.

+    mock_cb_.SetWebLayer(!!layer);
+  }
+
+  blink::WebMediaPlayer::TrackId addAudioTrack(const blink::WebString& id,
+                                               AudioTrackKind,
+                                               const blink::WebString& label,
+                                               const blink::WebString& language,
+                                               bool enabled) override {
+    return 0;
+  }
+  void removeAudioTrack(blink::WebMediaPlayer::TrackId) override {}
+
+  blink::WebMediaPlayer::TrackId addVideoTrack(const blink::WebString& id,
+                                               VideoTrackKind,
+                                               const blink::WebString& label,
+                                               const blink::WebString& language,
+                                               bool selected) override {
+    return 0;
+  }
+  void removeVideoTrack(blink::WebMediaPlayer::TrackId) override {}
+  void addTextTrack(blink::WebInbandTextTrack*) override {}
+  void removeTextTrack(blink::WebInbandTextTrack*) override {}
+  void mediaSourceOpened(blink::WebMediaSource*) override {}
+  void requestSeek(double) override {}
+  void remoteRouteAvailabilityChanged(bool) override {}
+  void connectedToRemoteDevice() override {}
+  void disconnectedFromRemoteDevice() override {}
+
+  // Implementation of cc::VideoFrameProvider::Client
+  void StopUsingProvider() {
+    if (rendering_)
+      StopRendering();
+  }
+
+  void StartRendering() {
+    if (!rendering_) {
+      rendering_ = true;
+      message_loop_.PostTask(FROM_HERE,
+                             base::Bind(&WebMediaPlayerMSTest::RenderFrame,
+                                        base::Unretained(this)));
+    }
+    mock_cb_.StartRendering();
+  }
+
+  void StopRendering() {
+    rendering_ = false;
+    mock_cb_.StopRendering();
+  }
+  void DidReceiveFrame() override {}
+  void DidUpdateMatrix(const float* matrix) override {}
+
+  // For test use
+  void SetBackgroundRendering(bool background_rendering) {
+    background_rendering_ = background_rendering;
+  }
+
+ protected:
+  // Use StrictMock<T> to catch missing/extra callbacks.
+  testing::StrictMock<MockCB> mock_cb_;
+
+  base::MessageLoop message_loop_;
+  MockRenderFactory* render_factory_;
+  WebMediaPlayerMS player_;
+  WebMediaPlayerMSCompositor* compositor_;
+
+  ReusableMessageLoopEvent message_loop_controller_;
+
+ private:
+  // Main function trying to ask WebMediaPlayerMS to submit a frame for
+  // rendering.
+  void RenderFrame() {
+    if (!rendering_ || !compositor_)
+      return;
+
+    base::TimeTicks now = base::TimeTicks::Now();
+    base::TimeTicks deadline_min =
+        now + base::TimeDelta::FromSecondsD(1.0 / 60.0);
+    base::TimeTicks deadline_max =
+        deadline_min + base::TimeDelta::FromSecondsD(1.0 / 60.0);
+
+    // Background rendering is different from stop rendering. The rendering loop
+    // is still running but we do not ask frames from compositor_. And
+    // background rendering is not initiated from compositor_.
+    if (!background_rendering_) {
+      compositor_->UpdateCurrentFrame(deadline_min, deadline_max);
+      auto frame = compositor_->GetCurrentFrame();
+      compositor_->PutCurrentFrame();
+    }
+    message_loop_.PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&WebMediaPlayerMSTest::RenderFrame, base::Unretained(this)),
+        base::TimeDelta::FromSecondsD(1.0 / 60.0));
+  }
+
+  bool rendering_;
+  bool background_rendering_;
+};
+
+TEST_F(WebMediaPlayerMSTest, Playing_Normal) {
+  // Workflow:
+  // 1. WMPMS::Load will generate and start content::VideoFrameProvider.
+  // 2. content::VideoFrameProvider will start pushing frames into WMPMS
+  //    repeatedly.
+  // 3. On WMPMS receiving the first frame, a WebLayer will be created.
+  // 4. The WebLayer will call WMPMSCompositor::SetVideoFrameProviderClient,
+  //    which in turn will trigger cc::VideoFrameProviderClient::StartRendering.
+  // 5. Then cc::VideoFrameProviderClient will start calling
+  //    WMPMSCompositor::UpdateCurrentFrame, GetCurrentFrame for rendering
+  //    repeatedly.
+  // 6. When WMPSMS::pause gets called, it should trigger
+  //    content::VideoFrameProvider::Pause, and then the provider will stop
+  //    pushing frames into WMPMS, but instead digesting them; simultanously, it
+  //    should call cc::VideoFrameProviderClient::StopRendering, so the client
+  //    will stop asking frames from WMPMSCompositor.
+  // 7. When WMPMS::play gets called, evething paused in step 6 should be
+  //    resumed.
+  MockVideoFrameProvider* provider = LoadAndGetFrameProvider(true);
+
+  int tokens[] = {0,   33,  66,  100, 133, 166, 200, 233, 266, 300,
+                  333, 366, 400, 433, 466, 500, 533, 566, 600};
+  std::vector<int> timestamps(tokens, tokens + sizeof(tokens) / sizeof(int));
+  provider->QueueFrames(timestamps);
+
+  EXPECT_CALL(mock_cb_, SetWebLayer(true));
+  EXPECT_CALL(mock_cb_, StartRendering());
+  EXPECT_CALL(mock_cb_,
+              ReadyStateChanged(blink::WebMediaPlayer::ReadyStateHaveMetadata));
+  EXPECT_CALL(mock_cb_, ReadyStateChanged(
+                            blink::WebMediaPlayer::ReadyStateHaveEnoughData));
+  message_loop_controller_.RunAndWaitForStatus(
+      media::PipelineStatus::PIPELINE_OK);
+  mock_cb_.VerifyAndClearExpectations();
+
+  EXPECT_CALL(mock_cb_, SetWebLayer(false));
+}
+
+TEST_F(WebMediaPlayerMSTest, Playing_ErrorFrame) {
+  MockVideoFrameProvider* provider = LoadAndGetFrameProvider(false);
+
+  int tokens[] = {0,   33,  66,  100, 133, 166, 200, 233, 266, 300,
+                  333, 366, 400, 433, 466, 500, 533, 566, 600, -1};
+  std::vector<int> timestamps(tokens, tokens + sizeof(tokens) / sizeof(int));
+  provider->QueueFrames(timestamps);
+
+  EXPECT_CALL(mock_cb_, SetWebLayer(true));
+  EXPECT_CALL(mock_cb_, StartRendering());
+  EXPECT_CALL(mock_cb_,
+              ReadyStateChanged(blink::WebMediaPlayer::ReadyStateHaveMetadata));
+  EXPECT_CALL(mock_cb_, ReadyStateChanged(
+                            blink::WebMediaPlayer::ReadyStateHaveEnoughData));
+  EXPECT_CALL(mock_cb_, NetworkStateChanged(
+                            blink::WebMediaPlayer::NetworkStateFormatError));
+  message_loop_controller_.RunAndWaitForStatus(
+      media::PipelineStatus::PIPELINE_ERROR_NETWORK);
+  mock_cb_.VerifyAndClearExpectations();
+
+  EXPECT_CALL(mock_cb_, SetWebLayer(false));
+}
+
+TEST_F(WebMediaPlayerMSTest, PlayThenPause) {
+  MockVideoFrameProvider* provider = LoadAndGetFrameProvider(false);
+
+  int tokens[] = {0,   33,  66,  100, 133, -2,  166, 200, 233, 266,
+                  300, 333, 366, 400, 433, 466, 500, 533, 566, 600};
+  std::vector<int> timestamps(tokens, tokens + sizeof(tokens) / sizeof(int));
+  provider->QueueFrames(timestamps);
+
+  EXPECT_CALL(mock_cb_, SetWebLayer(true));
+  EXPECT_CALL(mock_cb_, StartRendering());
+  EXPECT_CALL(mock_cb_,
+              ReadyStateChanged(blink::WebMediaPlayer::ReadyStateHaveMetadata));
+  EXPECT_CALL(mock_cb_, ReadyStateChanged(
+                            blink::WebMediaPlayer::ReadyStateHaveEnoughData));
+  // Rendering will be "paused" at the TestBrake.
+  message_loop_controller_.RunAndWaitForStatus(
+      media::PipelineStatus::PIPELINE_OK);
+  mock_cb_.VerifyAndClearExpectations();
+
+  // Here No more rendering. 1. Render should not be called, 2. Frame freeze.
+  EXPECT_CALL(mock_cb_, StopRendering());
+  player_.pause();
+  auto prev_frame = compositor_->GetCurrentFrame();
+  message_loop_controller_.RunAndWaitForStatus(
+      media::PipelineStatus::PIPELINE_OK);
+  auto after_frame = compositor_->GetCurrentFrame();
+  EXPECT_EQ(prev_frame->timestamp(), after_frame->timestamp());
+  mock_cb_.VerifyAndClearExpectations();
+
+  EXPECT_CALL(mock_cb_, SetWebLayer(false));
+}
+
+TEST_F(WebMediaPlayerMSTest, PlayThenPauseThenPlay) {
+  MockVideoFrameProvider* provider = LoadAndGetFrameProvider(false);
+
+  int tokens[] = {0,   33,  66,  100, 133, -2,  166, 200, 233, 266, 300,
+                  333, 366, 400, 433, -2,  466, 500, 533, 566, 600};
+  std::vector<int> timestamps(tokens, tokens + sizeof(tokens) / sizeof(int));
+  provider->QueueFrames(timestamps);
+
+  EXPECT_CALL(mock_cb_, SetWebLayer(true));
+  EXPECT_CALL(mock_cb_, StartRendering());
+  EXPECT_CALL(mock_cb_,
+              ReadyStateChanged(blink::WebMediaPlayer::ReadyStateHaveMetadata));
+  EXPECT_CALL(mock_cb_, ReadyStateChanged(
+                            blink::WebMediaPlayer::ReadyStateHaveEnoughData));
+  // Rendering will be "paused" at the TestBrake.
+  message_loop_controller_.RunAndWaitForStatus(
+      media::PipelineStatus::PIPELINE_OK);
+  mock_cb_.VerifyAndClearExpectations();
+
+  // Here No more rendering. 1. Render should not be called, 2. Frame freeze.
+  EXPECT_CALL(mock_cb_, StopRendering());
+  player_.pause();
+  auto prev_frame = compositor_->GetCurrentFrame();
+  message_loop_controller_.RunAndWaitForStatus(
+      media::PipelineStatus::PIPELINE_OK);
+  auto after_frame = compositor_->GetCurrentFrame();
+  EXPECT_EQ(prev_frame->timestamp(), after_frame->timestamp());
+  mock_cb_.VerifyAndClearExpectations();
+
+  // We resume the player
+  EXPECT_CALL(mock_cb_, StartRendering());
+  player_.play();
+  prev_frame = compositor_->GetCurrentFrame();
+  message_loop_controller_.RunAndWaitForStatus(
+      media::PipelineStatus::PIPELINE_OK);
+  after_frame = compositor_->GetCurrentFrame();
+  EXPECT_NE(prev_frame->timestamp(), after_frame->timestamp());
+  mock_cb_.VerifyAndClearExpectations();
+
+  EXPECT_CALL(mock_cb_, SetWebLayer(false));
+}
+
+TEST_F(WebMediaPlayerMSTest, BackgroudRendering) {
+  MockVideoFrameProvider* provider = LoadAndGetFrameProvider(true);
+
+  int tokens[] = {0,   33,  66,  100, 133, -2,  166, 200, 233, 266, 300,
+                  333, 366, 400, 433, -2,  466, 500, 533, 566, 600};
+  std::vector<int> timestamps(tokens, tokens + sizeof(tokens) / sizeof(int));
+  provider->QueueFrames(timestamps);
+
+  EXPECT_CALL(mock_cb_, SetWebLayer(true));
+  EXPECT_CALL(mock_cb_, StartRendering());
+  EXPECT_CALL(mock_cb_,
+              ReadyStateChanged(blink::WebMediaPlayer::ReadyStateHaveMetadata));
+  EXPECT_CALL(mock_cb_, ReadyStateChanged(
+                            blink::WebMediaPlayer::ReadyStateHaveEnoughData));
+  // Rendering will be "paused" at the TestBrake.
+  message_loop_controller_.RunAndWaitForStatus(
+      media::PipelineStatus::PIPELINE_OK);
+  mock_cb_.VerifyAndClearExpectations();
+
+  // Switch to background rendering, expect rendering to continue
+  SetBackgroundRendering(true);
+  auto prev_frame = compositor_->GetCurrentFrame();
+  message_loop_controller_.RunAndWaitForStatus(
+      media::PipelineStatus::PIPELINE_OK);
+  auto after_frame = compositor_->GetCurrentFrame();
+  EXPECT_NE(prev_frame->timestamp(), after_frame->timestamp());
+
+  // Switch to foreground rendering
+  SetBackgroundRendering(false);
+  prev_frame = compositor_->GetCurrentFrame();
+  message_loop_controller_.RunAndWaitForStatus(
+      media::PipelineStatus::PIPELINE_OK);
+  after_frame = compositor_->GetCurrentFrame();
+  EXPECT_NE(prev_frame->timestamp(), after_frame->timestamp());
+  mock_cb_.VerifyAndClearExpectations();
+
+  EXPECT_CALL(mock_cb_, SetWebLayer(false));
+}
+}  // namespace content