Rename Date to DateTime.

tests/corelib/is_operator_basic_types_test.dart

Index: tests/corelib/is_operator_basic_types_test.dart
diff --git a/tests/corelib/is_operator_basic_types_test.dart b/tests/corelib/is_operator_basic_types_test.dart
index 0e62b23c808b3c85e4792981d253eb263e137deb..e0771bbe36c92fe0be59cb3e038bdb144eb0699b 100644
--- a/tests/corelib/is_operator_basic_types_test.dart
+++ b/tests/corelib/is_operator_basic_types_test.dart
@@ -60,6 +60,6 @@ main() {
   check([[], 'string', null]);
 
   // Try to make it even harder.
-  var string = new String.fromCharCodes([new Date.now().year % 100 + 1]);
+  var string = new String.fromCharCodes([new DateTime.now().year % 100 + 1]);
   check([string.charCodes, string, null]);
 }