Reject re-inserting already decoded frames into FrameBuffer2.

webrtc/modules/video_coding/frame_buffer2.cc

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 192 matching lines @@
   }
 
   if (frame->inter_layer_predicted && frame->spatial_layer == 0) {
     LOG(LS_WARNING) << "Frame with (picture_id:spatial_id) (" << key.picture_id
                     << ":" << static_cast<int>(key.spatial_layer)
                     << ") is marked as inter layer predicted, dropping frame.";
     return last_continuous_picture_id;
   }
 
   if (last_decoded_frame_it_ != frames_.end() &&
-      key < last_decoded_frame_it_->first) {
+      key <= last_decoded_frame_it_->first) {
     if (AheadOf(frame->timestamp, last_decoded_frame_timestamp_) &&
         frame->num_references == 0) {
       // If this frame has a newer timestamp but an earlier picture id then we
       // assume there has been a jump in the picture id due to some encoder
       // reconfiguration or some other reason. Even though this is not according
       // to spec we can still continue to decode from this frame if it is a
       // keyframe.
       LOG(LS_WARNING) << "A jump in picture id was detected, clearing buffer.";
       ClearFramesAndHistory();
       last_continuous_picture_id = -1;
@@ skipping 216 matching lines @@
   frames_.clear();
   last_decoded_frame_it_ = frames_.end();
   last_continuous_frame_it_ = frames_.end();
   next_frame_it_ = frames_.end();
   num_frames_history_ = 0;
   num_frames_buffered_ = 0;
 }
 
 }  // namespace video_coding
 }  // namespace webrtc