Merge the dart:uri library into dart:core and update the Uri class

pkg/serialization/lib/src/serialization_rule.dart

Index: pkg/serialization/lib/src/serialization_rule.dart
diff --git a/pkg/serialization/lib/src/serialization_rule.dart b/pkg/serialization/lib/src/serialization_rule.dart
index 4ffe9663cea8eefeebf1e54546301035d1df844b..1c30725f768d97f64ce0723090539e04dc84024f 100644
--- a/pkg/serialization/lib/src/serialization_rule.dart
+++ b/pkg/serialization/lib/src/serialization_rule.dart
@@ -408,7 +408,7 @@ class MirrorRule extends NamedObjectRule {
     // So follow one or the other path depending if it has a colon, which we
     // assume is in any URI and can't be in a Symbol.
     if (name.contains(":")) {
-      var uri = new Uri(name);
+      var uri = Uri.parse(name);
       var libMirror = currentMirrorSystem().libraries[uri];
       return libMirror.classes[new Symbol(type)];
     } else {