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

webrtc/api/peerconnectioninterface_unittest.cc

 /*
  *  Copyright 2012 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 1809 matching lines @@
   rtc::scoped_refptr<DataChannelInterface> channel;
 
   config.id = 1;
   channel = pc_->CreateDataChannel("1", &config);
   EXPECT_TRUE(channel != NULL);
   EXPECT_EQ(1, channel->id());
 
   channel = pc_->CreateDataChannel("x", &config);
   EXPECT_TRUE(channel == NULL);
 
-  config.id = cricket::kMaxSctpSid;
+  config.id = cricket::kMaxSctpStreams - 1;
   channel = pc_->CreateDataChannel("max", &config);
   EXPECT_TRUE(channel != NULL);
   EXPECT_EQ(config.id, channel->id());
 
-  config.id = cricket::kMaxSctpSid + 1;
+  config.id = cricket::kMaxSctpStreams;
   channel = pc_->CreateDataChannel("x", &config);
   EXPECT_TRUE(channel == NULL);
 }
 
 // Verifies that duplicated label is allowed for SCTP data channel.
 TEST_F(PeerConnectionInterfaceTest, SctpDuplicatedLabelAllowed) {
   FakeConstraints constraints;
   constraints.AddMandatory(webrtc::MediaConstraintsInterface::kEnableDtlsSrtp,
                            true);
   CreatePeerConnection(&constraints);
@@ skipping 1042 matching lines @@
   FakeConstraints updated_answer_c;
   answer_c.SetMandatoryReceiveAudio(false);
   answer_c.SetMandatoryReceiveVideo(false);
 
   cricket::MediaSessionOptions updated_answer_options;
   EXPECT_TRUE(
       ParseConstraintsForAnswer(&updated_answer_c, &updated_answer_options));
   EXPECT_TRUE(updated_answer_options.has_audio());
   EXPECT_TRUE(updated_answer_options.has_video());
 }