FrameBuffer for the new jitter buffer.

BUG=webrtc:5514
R=danilchap@webrtc.org, mflodman@webrtc.org

Review URL: https://codereview.webrtc.org/1969403007 .

Cr-Commit-Position: refs/heads/master@{#12798}

webrtc/modules/video_coding/frame_object.cc

@@ -18,6 +18,7 @@ namespace video_coding {
 FrameObject::FrameObject()
     : picture_id(0),
       spatial_layer(0),
+      timestamp(0),
       num_references(0),
       inter_layer_predicted(false) {}