libvpx: Pull from upstream

source/libvpx/vp9/common/vp9_quant_common.c

 /*
  *  Copyright (c) 2010 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.
  */
 
@@ skipping 112 matching lines @@
 
 int16_t vp9_dc_quant(int qindex, int delta) {
   return dc_qlookup[clamp(qindex + delta, 0, MAXQ)];
 }
 
 int16_t vp9_ac_quant(int qindex, int delta) {
   return ac_qlookup[clamp(qindex + delta, 0, MAXQ)];
 }
 
 
-int vp9_get_qindex(struct segmentation *seg, int segment_id, int base_qindex) {
+int vp9_get_qindex(const struct segmentation *seg, int segment_id,
+                   int base_qindex) {
   if (vp9_segfeature_active(seg, segment_id, SEG_LVL_ALT_Q)) {
     const int data = vp9_get_segdata(seg, segment_id, SEG_LVL_ALT_Q);
     return seg->abs_delta == SEGMENT_ABSDATA ?
                              data :  // Abs value
                              clamp(base_qindex + data, 0, MAXQ);  // Delta value
   } else {
     return base_qindex;
   }
 }