Remove remnants of libsrtp1

webrtc/pc/externalhmac.h

Index: webrtc/pc/externalhmac.h
diff --git a/webrtc/pc/externalhmac.h b/webrtc/pc/externalhmac.h
index 091412e6a9e710d2aa108daccf227b35e1afacc1..f9f1a2cc6f7493d6747680cc2d56e6ca646fd3a5 100644
--- a/webrtc/pc/externalhmac.h
+++ b/webrtc/pc/externalhmac.h
@@ -30,26 +30,9 @@
 
 #include "webrtc/base/basictypes.h"
 #ifdef HAVE_SRTP
-extern "C" {
-#ifdef SRTP_RELATIVE_PATH
-#include "auth.h"  // NOLINT
-#else
 #include "third_party/libsrtp/crypto/include/auth.h"
-#endif  // SRTP_RELATIVE_PATH
-}
 #endif  // HAVE_SRTP
 
-#if defined(HAVE_SRTP) && !defined(SRTP_HMAC_SHA1)
-// Include compatibility shims to compile against libsrtp 1.x.
-// TODO(mattdr): Remove once Chromium uses libsrtp 2.
-
-// Remember that the definition of SRTP_HMAC_SHA1 is synthetic.
-#define COMPILING_AGAINST_LIBSRTP1 1
-
-#define SRTP_HMAC_SHA1 HMAC_SHA1
-#define srtp_auth_t auth_t
-#endif
-
 #if defined(HAVE_SRTP) && defined(ENABLE_EXTERNAL_AUTH)
 
 #define EXTERNAL_HMAC_SHA1 SRTP_HMAC_SHA1 + 1