Let AudioCodingModule::SendCodec return Maybe<CodecInst>

webrtc/modules/audio_coding/main/test/EncodeDecodeTest.cc

Index: webrtc/modules/audio_coding/main/test/EncodeDecodeTest.cc
diff --git a/webrtc/modules/audio_coding/main/test/EncodeDecodeTest.cc b/webrtc/modules/audio_coding/main/test/EncodeDecodeTest.cc
index d062af0fb9251257a7a5867f71a1546f23a0a0b3..d68e57532e0d92e715f7f60674e248b443deb4db 100644
--- a/webrtc/modules/audio_coding/main/test/EncodeDecodeTest.cc
+++ b/webrtc/modules/audio_coding/main/test/EncodeDecodeTest.cc
@@ -339,8 +339,7 @@ std::string EncodeDecodeTest::EncodeToFile(int fileType,
   _sender.codeId = codeId;
 
   _sender.Setup(acm.get(), &rtpFile, "audio_coding/testfile32kHz", 32000, 1);
-  struct CodecInst sendCodecInst;
-  if (acm->SendCodec(&sendCodecInst) >= 0) {
+  if (acm->SendCodec()) {
     _sender.Run();
   }
   _sender.Teardown();