Remove WebRtcVideoSendStream2::VideoSink inheritance. Remove sending black frame on source remova…

webrtc/media/engine/webrtcvideoengine2_unittest.cc

Index: webrtc/media/engine/webrtcvideoengine2_unittest.cc
diff --git a/webrtc/media/engine/webrtcvideoengine2_unittest.cc b/webrtc/media/engine/webrtcvideoengine2_unittest.cc
index 71156a6db0c93f8aa529cd956b687329a772bf2a..e13fc1c5ec40a1cec0ca127d3fdbc58aaaf5fe14 100644
--- a/webrtc/media/engine/webrtcvideoengine2_unittest.cc
+++ b/webrtc/media/engine/webrtcvideoengine2_unittest.cc
@@ -1557,8 +1557,7 @@ TEST_F(WebRtcVideoChannel2Test, UsesCorrectSettingsForScreencast) {
       << "Non-screenshare shouldn't use min-transmit bitrate.";
 
   EXPECT_TRUE(channel_->SetVideoSend(last_ssrc_, true, nullptr, nullptr));
-  // Removing a capturer triggers a black frame to be sent.
-  EXPECT_EQ(2, send_stream->GetNumberOfSwappedFrames());
+  EXPECT_EQ(1, send_stream->GetNumberOfSwappedFrames());
   VideoOptions screencast_options;
   screencast_options.is_screencast = rtc::Optional<bool>(true);
   EXPECT_TRUE(
@@ -1566,7 +1565,7 @@ TEST_F(WebRtcVideoChannel2Test, UsesCorrectSettingsForScreencast) {
   EXPECT_TRUE(capturer.CaptureFrame());
   // Send stream not recreated after option change.
   ASSERT_EQ(send_stream, fake_call_->GetVideoSendStreams().front());
-  EXPECT_EQ(3, send_stream->GetNumberOfSwappedFrames());
+  EXPECT_EQ(2, send_stream->GetNumberOfSwappedFrames());
 
   // Verify screencast settings.
   encoder_config = send_stream->GetEncoderConfig().Copy();