RtpRtcp allows to register header extension by name

webrtc/modules/rtp_rtcp/mocks/mock_rtp_rtcp.h

Index: webrtc/modules/rtp_rtcp/mocks/mock_rtp_rtcp.h
diff --git a/webrtc/modules/rtp_rtcp/mocks/mock_rtp_rtcp.h b/webrtc/modules/rtp_rtcp/mocks/mock_rtp_rtcp.h
index d4d6e1491cc15ad42e50b6e62f8527139e854697..7c84ccc678180226a3f4b991f771607ec85793cc 100644
--- a/webrtc/modules/rtp_rtcp/mocks/mock_rtp_rtcp.h
+++ b/webrtc/modules/rtp_rtcp/mocks/mock_rtp_rtcp.h
@@ -12,6 +12,7 @@
 #define WEBRTC_MODULES_RTP_RTCP_MOCKS_MOCK_RTP_RTCP_H_
 
 #include <set>
+#include <string>
 #include <utility>
 #include <vector>
 
@@ -78,6 +79,8 @@ class MockRtpRtcp : public RtpRtcp {
       int32_t(const int8_t payloadType));
   MOCK_METHOD2(RegisterSendRtpHeaderExtension,
       int32_t(const RTPExtensionType type, const uint8_t id));
+  MOCK_METHOD2(RegisterRtpHeaderExtension,
+               bool(const std::string& type, uint8_t id));
   MOCK_METHOD1(DeregisterSendRtpHeaderExtension,
       int32_t(const RTPExtensionType type));
   MOCK_CONST_METHOD0(StartTimestamp,