Convert Vp9 Rtp headers to frame references.

webrtc/modules/video_coding/frame_object.cc

Index: webrtc/modules/video_coding/frame_object.cc
diff --git a/webrtc/modules/video_coding/frame_object.cc b/webrtc/modules/video_coding/frame_object.cc
index 7a05d28d56e06229b5265596ea6a1ab973dd6881..6d4aea553d20c3eddd457f2367e9c37a50939918 100644
--- a/webrtc/modules/video_coding/frame_object.cc
+++ b/webrtc/modules/video_coding/frame_object.cc
@@ -15,6 +15,11 @@
 namespace webrtc {
 namespace video_coding {
 
+FrameObject::FrameObject() : picture_id(0),
+                             spatial_layer(0),
+                             num_references(0),
+                             inter_layer_predicted(false) {}
+
 RtpFrameObject::RtpFrameObject(PacketBuffer* packet_buffer,
                                uint16_t first_packet,
                                uint16_t last_packet)