Add data-URI support class to dart:core (next to Uri).

runtime/lib/uri_sources.gypi

Index: runtime/lib/uri_sources.gypi
diff --git a/sdk/lib/developer/developer_sources.gypi b/runtime/lib/uri_sources.gypi
similarity index 58%
copy from sdk/lib/developer/developer_sources.gypi
copy to runtime/lib/uri_sources.gypi
index 0c4333a309ac2c7220988a4b451379407b945d9e..215b56a1fa23ab352f8aceb9d34053c27bf775f9 100644
--- a/sdk/lib/developer/developer_sources.gypi
+++ b/runtime/lib/uri_sources.gypi
@@ -2,12 +2,11 @@
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
+# Sources visible via the dart:uri library.
+
 {
   'sources': [
-    'developer.dart',
-    'extension.dart',
-    'profiler.dart',
-    'timeline.dart',
-    # The above file needs to be first if additional parts are added to the lib.
+    'uri.cc',
+    'uri_patch.dart',
   ],
 }