[Windows] Upgrade to m97. (#977)

* Add PeerConnectionState.

* Cleanup when peerconnection disposed.

Author: cloudwebrtc

common/cpp/include/flutter_peerconnection.h

@@ -16,6 +16,7 @@ class FlutterPeerConnectionObserver : public RTCPeerConnectionObserver {
                                 std::string& peerConnectionId);
 
   virtual void OnSignalingState(RTCSignalingState state) override;
+  virtual void OnPeerConnectionState(RTCPeerConnectionState state) override;
   virtual void OnIceGatheringState(RTCIceGatheringState state) override;
   virtual void OnIceConnectionState(RTCIceConnectionState state) override;
   virtual void OnIceCandidate(

common/cpp/src/flutter_peerconnection.cc

@@ -255,6 +255,9 @@ void FlutterPeerConnection::RTCPeerConnectionDispose(
   auto it = base_->peerconnection_observers_.find(uuid);
   if (it != base_->peerconnection_observers_.end())
     base_->peerconnection_observers_.erase(it);
+  auto it2 = base_->peerconnections_.find(uuid);
+  if (it2 != base_->peerconnections_.end())
+    base_->peerconnections_.erase(it2);
   result->Success();
 }
 
@@ -900,6 +903,7 @@ static const char* signalingStateString(RTCSignalingState state) {
   }
   return "";
 }
+
 void FlutterPeerConnectionObserver::OnSignalingState(RTCSignalingState state) {
   if (event_sink_ != nullptr) {
     EncodableMap params;
@@ -909,6 +913,35 @@ void FlutterPeerConnectionObserver::OnSignalingState(RTCSignalingState state) {
   }
 }
 
+
+static const char *peerConnectionStateString(RTCPeerConnectionState state) {
+  switch (state) {
+    case RTCPeerConnectionStateNew:
+      return "new";
+    case RTCPeerConnectionStateConnecting:
+      return "connecting";
+    case RTCPeerConnectionStateConnected:
+      return "connected";
+    case RTCPeerConnectionStateDisconnected:
+      return "disconnected";
+    case RTCPeerConnectionStateFailed:
+      return "failed";
+    case RTCPeerConnectionStateClosed:
+      return "closed";
+  }
+  return "";
+}
+
+
+void FlutterPeerConnectionObserver::OnPeerConnectionState(RTCPeerConnectionState state) {
+  if (event_sink_ != nullptr) {
+    EncodableMap params;
+    params[EncodableValue("event")] = "peerConnectionState";
+    params[EncodableValue("state")] = peerConnectionStateString(state);
+    event_sink_->Success(EncodableValue(params));
+  }
+}
+
 static const char* iceGatheringStateString(RTCIceGatheringState state) {
   switch (state) {
     case RTCIceGatheringStateNew: