add -Iinclude/private anywhere we have -Isrc/core

gyp/svg.gyp

 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 {
   'targets': [
     {
       'target_name': 'svg',
       'product_name': 'skia_svg',
       'type': 'static_library',
       'standalone_static_library': 1,
       'dependencies': [
         'skia_lib.gyp:skia_lib',
         'xml.gyp:*',
       ],
       'include_dirs': [
+        '../include/private',
         '../include/svg',
         '../src/core',
       ],
       'sources': [
         '<(skia_include_path)/svg/SkSVGCanvas.h',
 
         '<(skia_src_path)/svg/SkSVGCanvas.cpp',
         '<(skia_src_path)/svg/SkSVGDevice.cpp',
         '<(skia_src_path)/svg/SkSVGDevice.h',
       ],
@@ skipping 78 matching lines @@
           '../src/svg/parser/SkSVG.cpp', # doesn't compile, maybe this is test code?
       ],
       'direct_dependent_settings': {
         'include_dirs': [
           '../include/svg/parser',
         ],
       },
     },
   ],
 }