Allow a received audio codec's payload type to change.

webrtc/media/engine/webrtcvoiceengine_unittest.cc

Index: webrtc/media/engine/webrtcvoiceengine_unittest.cc
diff --git a/webrtc/media/engine/webrtcvoiceengine_unittest.cc b/webrtc/media/engine/webrtcvoiceengine_unittest.cc
index 75b632016697c9a179e7770df89f82457944e597..68c1f98e4f00ab033f27c851ab112420861f646e 100644
--- a/webrtc/media/engine/webrtcvoiceengine_unittest.cc
+++ b/webrtc/media/engine/webrtcvoiceengine_unittest.cc
@@ -939,6 +939,18 @@ TEST_F(WebRtcVoiceEngineTestFake, AddRecvCodecsWhilePlaying) {
   EXPECT_EQ(kOpusCodec.id, gcodec.pltype);
 }
 
+// Test that we accept adding the same codec with a different payload type.
+// See: https://bugs.chromium.org/p/webrtc/issues/detail?id=5847
+TEST_F(WebRtcVoiceEngineTestFake, ChangeRecvCodecPayloadType) {
+  EXPECT_TRUE(SetupRecvStream());
+  cricket::AudioRecvParameters parameters;
+  parameters.codecs.push_back(kIsacCodec);
+  EXPECT_TRUE(channel_->SetRecvParameters(parameters));
+
+  ++parameters.codecs[0].id;
+  EXPECT_TRUE(channel_->SetRecvParameters(parameters));
+}
+
 TEST_F(WebRtcVoiceEngineTestFake, SetSendBandwidthAuto) {
   EXPECT_TRUE(SetupSendStream());