fixes detection of SDK libraries

lib/src/codegen/js_module_item_order.dart

Index: lib/src/codegen/js_module_item_order.dart
diff --git a/lib/src/codegen/js_module_item_order.dart b/lib/src/codegen/js_module_item_order.dart
index 072e170d1d76f7f102b33be933af148fa0abdbe4..48626a574e4cb45a19476b59da3a51a1c7018ee2 100644
--- a/lib/src/codegen/js_module_item_order.dart
+++ b/lib/src/codegen/js_module_item_order.dart
@@ -182,9 +182,9 @@ class ModuleItemLoadOrder {
     assert(library != _currentLibrary);
 
     // The SDK is a special case: we optimize the order to prevent laziness.
-    if (library.isInSdk) {
+    if (_isDartUri(library)) {
       // SDK is loaded before non-SDK libraries
-      if (!_currentLibrary.isInSdk) return true;
+      if (!_isDartUri(_currentLibrary)) return true;
 
       // Compute the order of both SDK libraries. If unknown, assume it's after.
       var order = corelibOrder.indexOf(library.name);
@@ -209,7 +209,7 @@ class ModuleItemLoadOrder {
   bool _inLibraryCycle(LibraryElement library) {
     // SDK libs don't depend on things outside the SDK.
     // (We can reach this via the recursive call below.)
-    if (library.isInSdk && !_currentLibrary.isInSdk) return false;
+    if (_isDartUri(library) && !_isDartUri(_currentLibrary)) return false;
 
     var result = _libraryCycleMemo[library];
     if (result != null) return result;
@@ -226,4 +226,10 @@ class ModuleItemLoadOrder {
     }
     return _libraryCycleMemo[library] = result;
   }
+
+  /// Returns whether this is a library imported with 'dart:' URI.
+  ///
+  /// This is similar to [LibraryElement.isInSdk], but checking the URI instead
+  /// of the library naming convention, because the URI is reliable.
+  static bool _isDartUri(LibraryElement e) => e.source.uri.scheme == 'dart';

[vsm, 2015/06/10 16:41:15]

Do you want to assert e.isInSdk == _isDartUri(e)?  It looks like you also fixed
the names.

[Jennifer Messerly, 2015/06/10 16:46:04]

We can't assert it, because user can name their library "dart.my.awesome.lib".
Unless we intend to make that an error? Doesn't seem worth it to me.

 }