Delete deprecated PeerConnection methods, and corresponding using declarations.

webrtc/api/peerconnectioninterface.h

Index: webrtc/api/peerconnectioninterface.h
diff --git a/webrtc/api/peerconnectioninterface.h b/webrtc/api/peerconnectioninterface.h
index 7dc8ace8c6b5352daa970759cbf30a9fc373f49e..412695dea83d6e777147b26bf88094646eff4f70 100644
--- a/webrtc/api/peerconnectioninterface.h
+++ b/webrtc/api/peerconnectioninterface.h
@@ -445,22 +445,16 @@ class PeerConnectionInterface : public rtc::RefCountInterface {
   // remote peer is notified.
   virtual void RemoveStream(MediaStreamInterface* stream) = 0;
 
-  // TODO(deadbeef): Make the following two methods pure virtual once
-  // implemented by all subclasses of PeerConnectionInterface.
   // Add a new MediaStreamTrack to be sent on this PeerConnection.
   // |streams| indicates which stream labels the track should be associated
   // with.
   virtual rtc::scoped_refptr<RtpSenderInterface> AddTrack(
       MediaStreamTrackInterface* track,
-      std::vector<MediaStreamInterface*> streams) {

[Taylor Brandstetter, 2017/01/16 23:44:57]

It doesn't look like chromium's mock PeerConnection overrides this yet:
https://cs.chromium.org/chromium/src/content/renderer/media/mock_peer_connect...

-    return nullptr;
-  }
+      std::vector<MediaStreamInterface*> streams) = 0;
 
   // Remove an RtpSender from this PeerConnection.
   // Returns true on success.
-  virtual bool RemoveTrack(RtpSenderInterface* sender) {
-    return false;
-  }
+  virtual bool RemoveTrack(RtpSenderInterface* sender) = 0;
 
   // Returns pointer to the created DtmfSender on success.
   // Otherwise returns NULL.
@@ -663,21 +657,15 @@ class PeerConnectionObserver {
   // pointer version.
 
   // Triggered when media is received on a new stream from remote peer.
-  virtual void OnAddStream(rtc::scoped_refptr<MediaStreamInterface> stream) {}
-  // Deprecated; please use the version that uses a scoped_refptr.
-  virtual void OnAddStream(MediaStreamInterface* stream) {}
+  virtual void OnAddStream(rtc::scoped_refptr<MediaStreamInterface> stream) = 0;
 
   // Triggered when a remote peer close a stream.
-  virtual void OnRemoveStream(rtc::scoped_refptr<MediaStreamInterface> stream) {
-  }
-  // Deprecated; please use the version that uses a scoped_refptr.
-  virtual void OnRemoveStream(MediaStreamInterface* stream) {}
+  virtual void OnRemoveStream(
+      rtc::scoped_refptr<MediaStreamInterface> stream) = 0;
 
   // Triggered when a remote peer opens a data channel.
   virtual void OnDataChannel(
-      rtc::scoped_refptr<DataChannelInterface> data_channel){};
-  // Deprecated; please use the version that uses a scoped_refptr.
-  virtual void OnDataChannel(DataChannelInterface* data_channel) {}
+      rtc::scoped_refptr<DataChannelInterface> data_channel) = 0;
 
   // Triggered when renegotiation is needed. For example, an ICE restart
   // has begun.