Reland Replace interface VideoCapturerInput with VideoSinkInterface.

webrtc/test/frame_generator.cc

Index: webrtc/test/frame_generator.cc
diff --git a/webrtc/test/frame_generator.cc b/webrtc/test/frame_generator.cc
index ed7e95a12679d2abc36da2e56a4e194206c7d198..dbf39c4e096f8c64a9b1b7ab4e2bf65ea5816c97 100644
--- a/webrtc/test/frame_generator.cc
+++ b/webrtc/test/frame_generator.cc
@@ -239,6 +239,27 @@ class ScrollingImageFrameGenerator : public FrameGenerator {
 
 }  // namespace
 
+FrameForwarder::FrameForwarder() : sink_(nullptr) {}
+
+void FrameForwarder::IncomingCapturedFrame(const VideoFrame& video_frame) {
+  rtc::CritScope lock(&crit_);
+  if (sink_)
+    sink_->OnFrame(video_frame);
+}
+
+void FrameForwarder::AddOrUpdateSink(rtc::VideoSinkInterface<VideoFrame>* sink,
+                                     const rtc::VideoSinkWants& wants) {
+  rtc::CritScope lock(&crit_);
+  RTC_DCHECK(!sink_ || sink_ == sink);
+  sink_ = sink;
+}
+
+void FrameForwarder::RemoveSink(rtc::VideoSinkInterface<VideoFrame>* sink) {
+  rtc::CritScope lock(&crit_);
+  RTC_DCHECK_EQ(sink, sink_);
+  sink_ = nullptr;
+}
+
 FrameGenerator* FrameGenerator::CreateChromaGenerator(size_t width,
                                                       size_t height) {
   return new ChromaGenerator(width, height);