Reland of Add framerate to VideoSinkWants and ability to signal on overuse

webrtc/test/frame_generator_capturer.h

Index: webrtc/test/frame_generator_capturer.h
diff --git a/webrtc/test/frame_generator_capturer.h b/webrtc/test/frame_generator_capturer.h
index 3b2355ff0d3ac1433bb2c40d983c62e2921d6fd1..36a79f9755da1f21f502a5b517f1b68376db64c2 100644
--- a/webrtc/test/frame_generator_capturer.h
+++ b/webrtc/test/frame_generator_capturer.h
@@ -77,6 +77,7 @@ class FrameGeneratorCapturer : public VideoCapturer {
 
   void InsertFrame();
   static bool Run(void* obj);
+  int GetCurrentConfiguredFramerate();
 
   Clock* const clock_;
   bool sending_;
@@ -86,7 +87,8 @@ class FrameGeneratorCapturer : public VideoCapturer {
   rtc::CriticalSection lock_;
   std::unique_ptr<FrameGenerator> frame_generator_;
 
-  int target_fps_;
+  int target_fps_ GUARDED_BY(&lock_);
+  rtc::Optional<int> wanted_fps_ GUARDED_BY(&lock_);
   VideoRotation fake_rotation_ = kVideoRotation_0;
 
   int64_t first_frame_capture_time_;