Replace SetCapturer and SetCaptureDevice by SetSource.

webrtc/api/videocapturertracksource.h

Index: webrtc/api/videocapturertracksource.h
diff --git a/webrtc/api/videocapturertracksource.h b/webrtc/api/videocapturertracksource.h
index 0d1142debada04403884321eaa3626fe9ecca972..1d9b98690c3b1429994d08105e41d066fee0fdd1 100644
--- a/webrtc/api/videocapturertracksource.h
+++ b/webrtc/api/videocapturertracksource.h
@@ -47,10 +47,6 @@ class VideoCapturerTrackSource : public VideoTrackSource,
       cricket::VideoCapturer* capturer,
       bool remote);
 
-  cricket::VideoCapturer* GetVideoCapturer() override {
-    return video_capturer_.get();
-  }
-
   bool is_screencast() const override {
     return video_capturer_->IsScreencast();
   }