Move direct use of VideoCapturer::VideoAdapter to VideoSinkWants.

webrtc/media/base/videosourceinterface.h

Index: webrtc/media/base/videosourceinterface.h
diff --git a/webrtc/media/base/videosourceinterface.h b/webrtc/media/base/videosourceinterface.h
index 14624585432194c74bec680c6f18befb56ce79f5..8895970df349bcb26eed18a78166470b2a6fac6c 100644
--- a/webrtc/media/base/videosourceinterface.h
+++ b/webrtc/media/base/videosourceinterface.h
@@ -13,20 +13,25 @@
 
 #include "webrtc/media/base/videosinkinterface.h"
 #include "webrtc/base/callback.h"
+#include "webrtc/base/optional.h"
 
 namespace rtc {
 
 // VideoSinkWants is used for notifying the source of properties a video frame
 // should have when it is delivered to a certain sink.
 struct VideoSinkWants {
-  bool operator==(const VideoSinkWants& rh) const {
-    return rotation_applied == rh.rotation_applied;
-  }
-  bool operator!=(const VideoSinkWants& rh) const { return !operator==(rh); }
-
   // Tells the source whether the sink wants frames with rotation applied.
   // By default, the rotation is applied by the source.
   bool rotation_applied = true;
+
+  // Tells the source the maximum number of pixels the sink wants.
+  rtc::Optional<int> max_pixel_count;
+  // Like |max_pixel_count| but relative to the given value. The source is
+  // requested to produce frames with a resolution one "step up" from the given
+  // value. In practice, this means that the sink can consume this amount of
+  // pixels but wants more and the source should produce a resolution one
+  // "step" higher than this but not higher.
+  rtc::Optional<int> max_pixel_count_step_up;
 };
 
 template <typename VideoFrameT>