Update NEON compiler flags for Skia to use the SK_ prefix.

skia/skia_common.gypi

 # Copyright 2013 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.
 
 # This gypi file handles the removal of platform-specific files from the
 # Skia build.
 {
   'includes': [
     # skia_for_chromium_defines.gypi defines skia_for_chromium_defines
     '../third_party/skia/gyp/skia_for_chromium_defines.gypi',
@@ skipping 93 matching lines @@
       'direct_dependent_settings': {
         'defines': [
           'SK_USE_POSIX_THREADS',
         ],
       },
     }],
 
     # Neon support.
     [ 'target_arch == "arm" and arm_version >= 7 and arm_neon == 1', {
       'defines': [
+        'SK_ARM_HAS_NEON',
         '__ARM_HAVE_NEON',
       ],
     }],
     [ 'target_arch == "arm" and arm_version >= 7 and arm_neon_optional == 1', {
       'defines': [
+        'SK_ARM_HAS_OPTIONAL_NEON',
         '__ARM_HAVE_OPTIONAL_NEON_SUPPORT',
       ],
     }],
   ],
 
   'variables': {
     'variables': {
       'conditions': [
         ['OS== "ios"', {
           'skia_support_gpu': 0,
@@ skipping 83 matching lines @@
   # re-export if they include Skia headers in their public headers.
   'all_dependent_settings': {
     'include_dirs': [
       '..',
       'config',
     ],
   },
 
   'msvs_disabled_warnings': [4244, 4267, 4341, 4345, 4390, 4554, 4748, 4800],
 }