Add content type information to encoded images and corresponding rtp extension header

webrtc/modules/include/module_common_types.h

Index: webrtc/modules/include/module_common_types.h
diff --git a/webrtc/modules/include/module_common_types.h b/webrtc/modules/include/module_common_types.h
index 98f7a38af204fe32a17e7c5f84b9d205c203dc2a..6382079e98a8bc55db11c469dba416728fe08c2a 100644
--- a/webrtc/modules/include/module_common_types.h
+++ b/webrtc/modules/include/module_common_types.h
@@ -58,6 +58,8 @@ struct RTPVideoHeader {
 
   PlayoutDelay playout_delay;
 
+  VideoContentType content_type;
+
   union {
     bool is_first_packet_in_frame;
     RTC_DEPRECATED bool isFirstPacket;  // first packet in frame
@@ -87,7 +89,7 @@ class RTPFragmentationHeader {
         fragmentationOffset(NULL),
         fragmentationLength(NULL),
         fragmentationTimeDiff(NULL),
-        fragmentationPlType(NULL) {};
+        fragmentationPlType(NULL) {}
 
   ~RTPFragmentationHeader() {
     delete[] fragmentationOffset;