diff --git a/talk/app/webrtc/videosourceinterface.h b/talk/app/webrtc/videosourceinterface.h
index 2b3a2e6..a90e3d5 100644
--- a/talk/app/webrtc/videosourceinterface.h
+++ b/talk/app/webrtc/videosourceinterface.h
@@ -45,9 +45,8 @@
   virtual cricket::VideoCapturer* GetVideoCapturer() = 0;
 
   // Stop the video capturer.
-  // TODO(perkj): Make pure virtual after updating Chrome.
-  virtual void Stop() {};
-  virtual void Restart() {};
+  virtual void Stop() = 0;
+  virtual void Restart() = 0;
 
   // Adds |output| to the source to receive frames.
   virtual void AddSink(cricket::VideoRenderer* output) = 0;