Rename Date to DateTime.

sdk/lib/html/html_common/conversions.dart

Index: sdk/lib/html/html_common/conversions.dart
diff --git a/sdk/lib/html/html_common/conversions.dart b/sdk/lib/html/html_common/conversions.dart
index f4d42adfbd8d103e5c0d34dd38192821fdae878e..b8d9183fd5b6bda5507ff53f152573dddc28edc6 100644
--- a/sdk/lib/html/html_common/conversions.dart
+++ b/sdk/lib/html/html_common/conversions.dart
@@ -117,9 +117,9 @@ _convertDartToNative_PrepareForStructuredClone(value) {
     if (e is bool) return e;
     if (e is num) return e;
     if (e is String) return e;
-    if (e is Date) {
+    if (e is DateTime) {
       // TODO(sra).
-      throw new UnimplementedError('structured clone of Date');
+      throw new UnimplementedError('structured clone of DateTime');
     }
     if (e is RegExp) {
       // TODO(sra).
@@ -265,7 +265,7 @@ convertNativeToDart_AcceptStructuredClone(object, {mustCopy = false}) {
 
     if (isJavaScriptDate(e)) {
       // TODO(sra).
-      throw new UnimplementedError('structured clone of Date');
+      throw new UnimplementedError('structured clone of DateTime');
     }
 
     if (isJavaScriptRegExp(e)) {