Adding more comments to every header file in api/ subdirectory.

webrtc/api/peerconnectionfactoryproxy.h

 /*
  *  Copyright 2014 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_API_PEERCONNECTIONFACTORYPROXY_H_
 #define WEBRTC_API_PEERCONNECTIONFACTORYPROXY_H_
 
 #include <memory>
 #include <string>
 #include <utility>
 
 #include "webrtc/api/peerconnectioninterface.h"
 #include "webrtc/api/proxy.h"
 #include "webrtc/base/bind.h"
 
 namespace webrtc {
 
+// TODO(deadbeef): Move this to .cc file and out of api/. What threads methods
+// are called on is an implementation detail.
 BEGIN_SIGNALING_PROXY_MAP(PeerConnectionFactory)
   PROXY_SIGNALING_THREAD_DESTRUCTOR()
   PROXY_METHOD1(void, SetOptions, const Options&)
   PROXY_METHOD5(rtc::scoped_refptr<PeerConnectionInterface>,
                 CreatePeerConnection,
                 const PeerConnectionInterface::RTCConfiguration&,
                 const MediaConstraintsInterface*,
                 std::unique_ptr<cricket::PortAllocator>,
                 std::unique_ptr<rtc::RTCCertificateGeneratorInterface>,
                 PeerConnectionObserver*);
@@ skipping 28 matching lines @@
   // TODO(ivoc): Remove the StartRtcEventLog and StopRtcEventLog functions as
   // soon as they are removed from PeerConnectionFactoryInterface.
   PROXY_METHOD1(bool, StartRtcEventLog, rtc::PlatformFile)
   PROXY_METHOD2(bool, StartRtcEventLog, rtc::PlatformFile, int64_t)
   PROXY_METHOD0(void, StopRtcEventLog)
 END_PROXY_MAP()
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_PEERCONNECTIONFACTORYPROXY_H_