remove SK_SUPPORT_LEGACY_SK64, as all call-sites have been updated

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.
 {
   'include_dirs': [
     '..',
     'config',
@@ skipping 127 matching lines @@
     # This list will contain all defines that also need to be exported to
     # dependent components.
     'skia_export_defines': [
       'SK_ENABLE_INST_COUNT=0',
       'SK_SUPPORT_GPU=<(skia_support_gpu)',
       'GR_GL_CUSTOM_SETUP_HEADER="GrGLConfig_chrome.h"',
       'SK_ENABLE_LEGACY_API_ALIASING=1',
       'SK_ATTR_DEPRECATED=SK_NOTHING_ARG1',
       'SK_SUPPORT_LEGACY_COLORTYPE=1',
       'GR_GL_IGNORE_ES3_MSAA=0',
-      'SK_SUPPORT_LEGACY_SK64',
       'SK_SUPPORT_LEGACY_ONLOCKPIXELS',
     ],
 
     'default_font_cache_limit%': '(20*1024*1024)',
 
     'conditions': [
       ['OS== "android"', {
         # Android devices are typically more memory constrained, so
         # default to a smaller glyph cache (it may be overriden at runtime
         # when the renderer starts up, depending on the actual device memory).
@@ skipping 47 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],
 }