binding: Lets Dictionary::getPropertyNames, etc. rethrow an exception.

third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.idl

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 77 matching lines @@
     // TODO(guidou): close() should never throw an exception.
     [RaisesException] void close();
     attribute EventHandler onnegotiationneeded;
     attribute EventHandler onicecandidate;
     attribute EventHandler onsignalingstatechange;
     attribute EventHandler oniceconnectionstatechange;
     // attribute EventHandler onicegatheringstatechange;
 
     // https://w3c.github.io/webrtc-pc/#legacy-interface-extensions
     // These methods return Promise<void> because having Promise-based versions requires that all overloads return Promises.
-    [CallWith=ScriptState] Promise<void> createOffer(RTCSessionDescriptionCallback successCallback, RTCPeerConnectionErrorCallback failureCallback, optional Dictionary rtcOfferOptions);
+    [CallWith=ScriptState, RaisesException] Promise<void> createOffer(RTCSessionDescriptionCallback successCallback, RTCPeerConnectionErrorCallback failureCallback, optional Dictionary rtcOfferOptions);
     // TODO(guidou): There should be no mediaConstraints argument.
     [CallWith=ScriptState] Promise<void> createAnswer(RTCSessionDescriptionCallback successCallback, RTCPeerConnectionErrorCallback failureCallback, optional Dictionary mediaConstraints);
     [CallWith=ScriptState] Promise<void> setLocalDescription(RTCSessionDescriptionInit description, VoidCallback successCallback, [Default=Undefined] optional RTCPeerConnectionErrorCallback failureCallback);
     // TODO(guidou): The failureCallback argument should be non-optional.
     [CallWith=ScriptState] Promise<void> setRemoteDescription(RTCSessionDescriptionInit description, VoidCallback successCallback, [Default=Undefined] optional RTCPeerConnectionErrorCallback failureCallback);
     [CallWith=ScriptState, MeasureAs=RTCPeerConnectionAddIceCandidateLegacy] Promise<void> addIceCandidate((RTCIceCandidateInit or RTCIceCandidate) candidate, VoidCallback successCallback, RTCPeerConnectionErrorCallback failureCallback);
 
     // TODO(guidou): The selector argument should the first (nullable,
     // non-optional) argument, and there should be a third failureCallback
     // argument.
@@ skipping 14 matching lines @@
     [Measure, CallWith=ExecutionContext, RaisesException] void updateIce(optional RTCConfiguration configuration, optional Dictionary mediaConstraints);
     [Measure] sequence<MediaStream> getLocalStreams();
     [Measure] sequence<MediaStream> getRemoteStreams();
     [Measure] MediaStream getStreamById(DOMString streamId);
     [Measure, CallWith=ExecutionContext, RaisesException] void addStream(MediaStream? stream, optional Dictionary mediaConstraints);
     [Measure, RaisesException] void removeStream(MediaStream? stream);
     [Measure, RaisesException] RTCDTMFSender createDTMFSender(MediaStreamTrack track);
     attribute EventHandler onaddstream;
     attribute EventHandler onremovestream;
 };