disable c4267 for hunspell for building on win x64

TBR=jschuh@chromium.org
BUG=167187

Review URL: https://chromiumcodereview.appspot.com/11823057

git-svn-id: http://src.chromium.org/svn/trunk/deps/third_party/hunspell@176100 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
diff --git a/hunspell.gyp b/hunspell.gyp
index a297cf8..ff76c3b 100644
--- a/hunspell.gyp
+++ b/hunspell.gyp
@@ -63,6 +63,8 @@
           'USE_HUNSPELL',
         ],
       },
+      # TODO(jschuh): http://crbug.com/167187 size_t -> int
+      'msvs_disabled_warnings': [ 4267 ],
       'conditions': [
         ['os_posix == 1 and OS != "mac"', {
           'cflags': [