Disable VS warnings in speex.

This is to eventually enable warnings as error
Review URL: http://codereview.chromium.org/6903072

git-svn-id: http://src.chromium.org/svn/trunk/deps/third_party/speex@83190 4ff67af0-8c30-449e-8e8b-ad334ec8d88c
diff --git a/speex.gyp b/speex.gyp
index 1afd70e..b98c56b 100644
--- a/speex.gyp
+++ b/speex.gyp
@@ -87,6 +87,7 @@
               'include',  # Clients expect <speex/speex.h> to be a system header.
             ],
           },
+          'msvs_disabled_warnings': [4244, 4305],
         },
       ],
     }, { # use_system_speex != 0