Fixing off-by-one error with max SCTP id.

webrtc/api/webrtcsdp.cc

 /*
  *  Copyright 2011 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.
  */
 
@@ skipping 1373 matching lines @@
 
 void BuildSctpContentAttributes(std::string* message, int sctp_port) {
   // draft-ietf-mmusic-sctp-sdp-04
   // a=sctpmap:sctpmap-number  protocol  [streams]
   // TODO(lally): switch this over to mmusic-sctp-sdp-12 (or later), with
   // 'a=sctp-port:'
   std::ostringstream os;
   InitAttrLine(kAttributeSctpmap, &os);
   os << kSdpDelimiterColon << sctp_port << kSdpDelimiterSpace
      << kDefaultSctpmapProtocol << kSdpDelimiterSpace
-     << (cricket::kMaxSctpSid + 1);
+     << cricket::kMaxSctpStreams;
   AddLine(os.str(), message);
 }
 
 // If unified_plan_sdp is true, will use "a=msid".
 void BuildRtpContentAttributes(const MediaContentDescription* media_desc,
                                const MediaType media_type,
                                bool unified_plan_sdp,
                                std::string* message) {
   std::ostringstream os;
   // RFC 5285
@@ skipping 1772 matching lines @@
     UpdateCodec<AudioContentDescription, cricket::AudioCodec>(
         media_desc, payload_type, feedback_param);
   } else if (media_type == cricket::MEDIA_TYPE_VIDEO) {
     UpdateCodec<VideoContentDescription, cricket::VideoCodec>(
         media_desc, payload_type, feedback_param);
   }
   return true;
 }
 
 }  // namespace webrtc