sdp: remove some unused x-google attributes

removes the unused
  x-google-port
  x-google-max-message-size
which were probably sctp-related and variants of max-message-size
and sctp-port parameters. Similarly for the
  protocol
  streams
parameters which seem to have been fmtp parameters.

BUG=chromium:943975

Change-Id: I21b543f717d6e12fd737f91c7e159362488cc2e0
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/198122
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32866}
diff --git a/media/base/media_constants.cc b/media/base/media_constants.cc
index 8c2c3bc..fb34ea8 100644
--- a/media/base/media_constants.cc
+++ b/media/base/media_constants.cc
@@ -56,9 +56,6 @@
 const char kCodecParamMaxAverageBitrate[] = "maxaveragebitrate";
 const char kCodecParamMaxPlaybackRate[] = "maxplaybackrate";
 
-const char kCodecParamSctpProtocol[] = "protocol";
-const char kCodecParamSctpStreams[] = "streams";
-
 const char kParamValueTrue[] = "1";
 const char kParamValueEmpty[] = "";
 
@@ -92,8 +89,6 @@
 const char kCodecParamMinBitrate[] = "x-google-min-bitrate";
 const char kCodecParamStartBitrate[] = "x-google-start-bitrate";
 const char kCodecParamMaxQuantization[] = "x-google-max-quantization";
-const char kCodecParamPort[] = "x-google-port";
-const char kCodecParamMaxMessageSize[] = "x-google-max-message-size";
 
 const int kGoogleRtpDataCodecPlType = 109;
 const char kGoogleRtpDataCodecName[] = "google-data";
diff --git a/media/base/media_constants.h b/media/base/media_constants.h
index ec656a9..6907172 100644
--- a/media/base/media_constants.h
+++ b/media/base/media_constants.h
@@ -61,8 +61,6 @@
 extern const char kCodecParamUseDtx[];
 extern const char kCodecParamMaxAverageBitrate[];
 extern const char kCodecParamMaxPlaybackRate[];
-extern const char kCodecParamSctpProtocol[];
-extern const char kCodecParamSctpStreams[];
 
 extern const char kParamValueTrue[];
 // Parameters are stored as parameter/value pairs. For parameters who do not
@@ -115,8 +113,6 @@
 extern const char kCodecParamMinBitrate[];
 extern const char kCodecParamStartBitrate[];
 extern const char kCodecParamMaxQuantization[];
-extern const char kCodecParamPort[];
-extern const char kCodecParamMaxMessageSize[];
 
 // We put the data codec names here so callers of DataEngine::CreateChannel
 // don't have to import rtpdataengine.h to get the codec names they want to