change scale down by 4 to use rounding.

libyuv.gyp

 # Copyright 2011 The LibYuv 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.
 
 {
   'includes': [
@@ skipping 29 matching lines @@
        }],
     ],
   },
 
   'targets': [
     {
       'target_name': 'libyuv',
       # Change type to 'shared_library' to build .so or .dll files.
       'type': 'static_library',
       'variables': {
-        'optimize': 'max',  # enable O2 and ltcg.
+ #       'optimize': 'max',  # enable O2 and ltcg.
       },
       # Allows libyuv.a redistributable library without external dependencies.
       'standalone_static_library': 1,
       'conditions': [
         ['build_neon != 0', {
           'defines': [
             'LIBYUV_NEON',
           ],
           'cflags!': [
             '-mfpu=vfp',
@@ skipping 84 matching lines @@
       ],
     },
   ], # targets.
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: