Fix no_size_t_to_int_warning in rtp_rtcp:rtp_rtcp_format target

webrtc/modules/rtp_rtcp/source/rtp_packet.h

 /*
  *  Copyright (c) 2016 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.
  */
 #ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_PACKET_H_
 #define WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_PACKET_H_
 
 #include <vector>
 
 #include "webrtc/api/array_view.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 #include "webrtc/rtc_base/basictypes.h"
 #include "webrtc/rtc_base/copyonwritebuffer.h"
 
 namespace webrtc {
 class RtpHeaderExtensionMap;
 class Random;
 
 namespace rtp {
 class Packet {
  public:
   using ExtensionType = RTPExtensionType;
   using ExtensionManager = RtpHeaderExtensionMap;
-  static constexpr size_t kMaxExtensionHeaders = 14;
+  static constexpr int kMaxExtensionHeaders = 14;
   static constexpr int kMinExtensionId = 1;
   static constexpr int kMaxExtensionId = 14;
 
   // Parse and copy given buffer into Packet.
   bool Parse(const uint8_t* buffer, size_t size);
   bool Parse(rtc::ArrayView<const uint8_t> packet);
 
   // Parse and move given buffer into Packet.
   bool Parse(rtc::CopyOnWriteBuffer packet);
 
@@ skipping 152 matching lines @@
   auto buffer = AllocateExtension(Extension::kId, Extension::kValueSizeBytes);
   if (buffer.empty())
     return false;
   memset(buffer.data(), 0, Extension::kValueSizeBytes);
   return true;
 }
 }  // namespace rtp
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_PACKET_H_