Remove RtpPacketToSend::GetHeader as almost unused.

webrtc/modules/rtp_rtcp/source/rtp_packet.h

Index: webrtc/modules/rtp_rtcp/source/rtp_packet.h
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_packet.h b/webrtc/modules/rtp_rtcp/source/rtp_packet.h
index 87974178346a68de8ec55071985ca48f4879f15e..fb19815b59343ee8ed35dcabf45936ea29f4236f 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_packet.h
+++ b/webrtc/modules/rtp_rtcp/source/rtp_packet.h
@@ -18,7 +18,6 @@
 #include "webrtc/rtc_base/copyonwritebuffer.h"
 
 namespace webrtc {
-struct RTPHeader;
 class RtpHeaderExtensionMap;
 class Random;
 
@@ -49,10 +48,6 @@ class Packet {
   uint32_t Ssrc() const;
   std::vector<uint32_t> Csrcs() const;
 
-  // TODO(danilchap): Remove this function when all code update to use RtpPacket
-  // directly. Function is there just for easier backward compatibilty.
-  void GetHeader(RTPHeader* header) const;
-
   size_t headers_size() const;
 
   // Payload.
@@ -127,7 +122,7 @@ class Packet {
   explicit Packet(const ExtensionManager* extensions);
   Packet(const Packet&);
   Packet(const ExtensionManager* extensions, size_t capacity);
-  virtual ~Packet();
+  ~Packet();
 
   Packet& operator=(const Packet&) = default;