Break rtp_rtcp_format out of rtp_rtcp, to resolve circular dependencies

webrtc/modules/rtp_rtcp/source/rtp_header_extension_map.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/modules/rtp_rtcp/include/rtp_header_extension_map.h"
 
+#include "webrtc/modules/rtp_rtcp/source/byte_io.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h"
-#include "webrtc/modules/rtp_rtcp/source/rtp_utility.h"
 #include "webrtc/rtc_base/arraysize.h"
 #include "webrtc/rtc_base/checks.h"
 #include "webrtc/rtc_base/logging.h"
 
 namespace webrtc {
 namespace {
 
-using RtpUtility::Word32Align;
-
 struct ExtensionInfo {
   RTPExtensionType type;
   const char* uri;
 };
 
 template <typename Extension>
 constexpr ExtensionInfo CreateExtensionInfo() {
   return {Extension::kId, Extension::kUri};
 }
 
@@ skipping 106 matching lines @@
     return false;
   }
   RTC_DCHECK(!IsRegistered(type));
 
   types_[id] = type;
   ids_[type] = id;
   return true;
 }
 
 }  // namespace webrtc