skip neon code in libwebp when neon is explicitly unavailable

third_party/libwebp/libwebp.gyp

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'targets': [
     {
       'target_name': 'libwebp_dec',
       'type': 'static_library',
       'dependencies' : [
@@ skipping 48 matching lines @@
             ['_toolset=="target"', {
               'cflags!': [ '-finstrument-functions' ],
             }],
           ],
         }],
       ],
     },
     {
       'target_name': 'libwebp_dsp_neon',
       'conditions': [
-        ['target_arch == "arm" and arm_version >= 7', {
+        ['target_arch == "arm" and arm_version >= 7 and (arm_neon == 1 or arm_neon_optional == 1)', {
           'type': 'static_library',
           'include_dirs': ['.'],
           'sources': [
             'dsp/dec_neon.c',
             'dsp/enc_neon.c',
             'dsp/upsampling_neon.c',
           ],
           # behavior similar to *.c.neon in an Android.mk
           'cflags!': [ '-mfpu=vfpv3-d16' ],
           'cflags': [ '-mfpu=neon' ],
@@ skipping 64 matching lines @@
       ],
       'direct_dependent_settings': {
         'include_dirs': ['.'],
       },
       'conditions': [
         ['OS!="win"', {'product_name': 'webp'}],
       ],
     },
   ],
 }