Fix standalone build.

BUG=20
R=jschuh@chromium.org

Review URL: https://codereview.chromium.org/349033008
diff --git a/build/standalone.gypi b/build/standalone.gypi
index bcc8cbc..967db1e 100644
--- a/build/standalone.gypi
+++ b/build/standalone.gypi
@@ -224,6 +224,7 @@
     ['OS=="win"', {
       'target_defaults': {
         'defines': [
+          'NOMINMAX',
           '_CRT_SECURE_NO_DEPRECATE',
           '_CRT_NONSTDC_NO_DEPRECATE',
         ],