libvpx: Pull from upstream

source/libvpx/vp9/encoder/vp9_svc_layercontext.c

 /*
  *  Copyright (c) 2014 The WebM 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.
  */
 
 #include <math.h>
 
 #include "vp9/encoder/vp9_encoder.h"
 #include "vp9/encoder/vp9_svc_layercontext.h"
 #include "vp9/encoder/vp9_extend.h"
+#include "vpx_dsp/vpx_dsp_common.h"
 
 #define SMALL_FRAME_FB_IDX 7
 #define SMALL_FRAME_WIDTH  32
 #define SMALL_FRAME_HEIGHT 16
 
 void vp9_init_layer_context(VP9_COMP *const cpi) {
   SVC *const svc = &cpi->svc;
   const VP9EncoderConfig *const oxcf = &cpi->oxcf;
   int sl, tl;
   int alt_ref_idx = svc->number_spatial_layers;
@@ skipping 608 matching lines @@
     buf = vp9_lookahead_peek(ctx, 0);
     if (buf != NULL) {
       // Only remove the buffer when pop the highest layer.
       if (cpi->svc.spatial_layer_id == cpi->svc.number_spatial_layers - 1) {
         vp9_lookahead_pop(ctx, drain);
       }
     }
   }
   return buf;
 }