Adding cbr support for Opus

webrtc/media/base/mediaconstants.h

Index: webrtc/media/base/mediaconstants.h
diff --git a/webrtc/media/base/mediaconstants.h b/webrtc/media/base/mediaconstants.h
index 44d8c7ee0113a2b1fddaf500513ab19ffec857a0..7424405c114ab2506ad2b3e73cd96a8893e97cd0 100644
--- a/webrtc/media/base/mediaconstants.h
+++ b/webrtc/media/base/mediaconstants.h
@@ -55,6 +55,7 @@ extern const char kCodecParamSPropStereo[];
 extern const char kCodecParamStereo[];
 extern const char kCodecParamUseInbandFec[];
 extern const char kCodecParamUseDtx[];
+extern const char kCodecParamUseCbr[];
 extern const char kCodecParamMaxAverageBitrate[];
 extern const char kCodecParamMaxPlaybackRate[];
 extern const char kCodecParamSctpProtocol[];
@@ -75,6 +76,7 @@ extern const int kOpusDefaultSPropStereo;
 extern const int kOpusDefaultStereo;
 extern const int kOpusDefaultUseInbandFec;
 extern const int kOpusDefaultUseDtx;
+extern const int kOpusDefaultUseCbr;
 extern const int kOpusDefaultMaxPlaybackRate;
 
 // Prefered values in this code base. Note that they may differ from the default