Add gyp files to build NSS in Dart

runtime/bin/bin.gypi

Index: runtime/bin/bin.gypi
diff --git a/runtime/bin/bin.gypi b/runtime/bin/bin.gypi
index c851c9757a7383021ec6bb7fdd95b1b5c3cc3edc..edfd17a725daa86e73d5046caa5674d0989e110e 100644
--- a/runtime/bin/bin.gypi
+++ b/runtime/bin/bin.gypi
@@ -260,6 +260,7 @@
         'generate_json_cc_file',
         'generate_uri_cc_file',
         'generate_utf_cc_file',
+        'nss',
       ],
       'include_dirs': [
         '..',
@@ -303,6 +304,19 @@
       ],
     },
     {
+      'target_name': 'nss',
+      'type': 'none',
+      'dependencies': [
+        'bin/net/nss.gyp:nss',
+        'bin/net/nss.gyp:nspr',
+        'bin/net/nss.gyp:nssckbi',
+        'bin/net/nss.gyp:nss_static',
+        'bin/net/ssl.gyp:libssl',
+        'bin/net/zlib.gyp:zlib',
+        'bin/net/sqlite.gyp:sqlite',
+      ],
+    },
+    {
       'target_name': 'libdart_withcore',
       'type': 'static_library',
       'dependencies': [