Add json-stringifier.h to v8.gyp.

R=jkummerow@chromium.org
BUG=

Review URL: https://chromiumcodereview.appspot.com/11267006

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12805 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

tools/gyp/v8.gyp

@@ -353,6 +353,7 @@
             '../../src/isolate.cc',
             '../../src/isolate.h',
             '../../src/json-parser.h',
+            '../../src/json-stringifier.h',
             '../../src/jsregexp.cc',
             '../../src/jsregexp.h',
             '../../src/lazy-instance.h',