Change gyp flag from in_dartium to dart_io_support.

runtime/bin/bin.gypi

Index: runtime/bin/bin.gypi
diff --git a/runtime/bin/bin.gypi b/runtime/bin/bin.gypi
index a96345e2c3bc965043e0ef414dd4161b0ffb00c6..00358fd291da4d56936454360bc5a59aaae85abf 100644
--- a/runtime/bin/bin.gypi
+++ b/runtime/bin/bin.gypi
@@ -306,9 +306,6 @@
     {
       'target_name': 'libdart_io',
       'type': 'static_library',
-      'dependencies': [
-        'nss_runtime',
-      ],
       'include_dirs': [
         '..',
       ],
@@ -320,6 +317,11 @@
         'io_impl_sources.gypi',
       ],
       'conditions': [
+        [ 'dart_io_support==1', {
+          'dependencies': [
+            'bin/net/ssl.gyp:libssl_dart',
+          ],
+        }],
         ['OS=="win"', {
           # TODO(antonm): fix the implementation.
           # Current implementation accepts char* strings
@@ -337,30 +339,6 @@
       ],
     },
     {
-      'target_name': 'nss_runtime',
-      'type': 'none',
-      'conditions': [[ 'in_dartium==0', {
-        'dependencies': [
-          'bin/net/nss.gyp:nss_dart',
-          'bin/net/nss.gyp:nspr_dart',
-          'bin/net/nss.gyp:nssckbi_dart',
-          'bin/net/nss.gyp:nss_static_dart',
-          'bin/net/ssl.gyp:libssl_dart',
-          'bin/net/zlib.gyp:zlib_dart',
-          'bin/net/sqlite.gyp:sqlite_dart',
-        ],
-        'export_dependent_settings': [
-          'bin/net/nss.gyp:nss_dart',
-          'bin/net/nss.gyp:nspr_dart',
-          'bin/net/nss.gyp:nssckbi_dart',
-          'bin/net/nss.gyp:nss_static_dart',
-          'bin/net/ssl.gyp:libssl_dart',
-          'bin/net/zlib.gyp:zlib_dart',
-          'bin/net/sqlite.gyp:sqlite_dart',
-        ],
-      }]],
-    },
-    {
       'target_name': 'libdart_withcore',
       'type': 'static_library',
       'dependencies': [