Let ViEEncoder express resolution requests as Sinkwants

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 fa001c4edff071a3da446e3aaad95538ece842d2..01bc04b688c66348471cf2ae22bdaa290faed9b9 100644
--- a/webrtc/test/frame_generator_capturer.h
+++ b/webrtc/test/frame_generator_capturer.h
@@ -31,6 +31,17 @@ class FrameGenerator;
 
 class FrameGeneratorCapturer : public VideoCapturer {
  public:
+  class SinkWantsObserver {
+   public:
+    // OnSinkWantsChanged is called when FrameGeneratorCapturer::AddOrUpdateSink
+    // is called.
+    virtual void OnSinkWantsChanged(rtc::VideoSinkInterface<VideoFrame>* sink,
+                                    const rtc::VideoSinkWants& wants) = 0;
+
+   protected:
+    virtual ~SinkWantsObserver() {}
+  };
+
   static FrameGeneratorCapturer* Create(size_t width,
                                         size_t height,
                                         int target_fps,
@@ -47,6 +58,8 @@ class FrameGeneratorCapturer : public VideoCapturer {
   void Stop() override;
   void ChangeResolution(size_t width, size_t height);
 
+  void SetSinkWantsObserver(SinkWantsObserver* observer);
+
   void AddOrUpdateSink(rtc::VideoSinkInterface<VideoFrame>* sink,
                        const rtc::VideoSinkWants& wants) override;
   void RemoveSink(rtc::VideoSinkInterface<VideoFrame>* sink) override;
@@ -68,6 +81,7 @@ class FrameGeneratorCapturer : public VideoCapturer {
   Clock* const clock_;
   bool sending_;
   rtc::VideoSinkInterface<VideoFrame>* sink_ GUARDED_BY(&lock_);
+  SinkWantsObserver* sink_wants_observer_ GUARDED_BY(&lock_);
 
   std::unique_ptr<EventTimerWrapper> tick_;
   rtc::CriticalSection lock_;