[dart2dart] Support cosntructor redirects.

lib/compiler/implementation/dart_backend/renamer.dart

Index: lib/compiler/implementation/dart_backend/renamer.dart
diff --git a/lib/compiler/implementation/dart_backend/renamer.dart b/lib/compiler/implementation/dart_backend/renamer.dart
index fc1a477a5ef324b68d0548d148d158c390bb8ead..52bbc58588b5d34462da7391c04f92a54e22da92 100644
--- a/lib/compiler/implementation/dart_backend/renamer.dart
+++ b/lib/compiler/implementation/dart_backend/renamer.dart
@@ -101,7 +101,7 @@ void renamePlaceholders(
     return result.toString();
   }
 
-  String renameConstructor(Element element, DartType type,
+  String renameConstructor(Element element, ConstructorPlaceholder placeholder,
       Function renameString, Function renameElement) {
     assert(element.isConstructor());
     StringBuffer result = new StringBuffer();
@@ -109,8 +109,10 @@ void renamePlaceholders(
     if (element.name != element.getEnclosingClass().name) {
       // Named constructor or factory. Is there a more reliable way to check
       // this case?
-      result.add(renameType(type, renameElement));
-      result.add('.');
+      if (!placeholder.isRedirectingCall) {
+        result.add(renameType(placeholder.type, renameElement));
+        result.add('.');
+      }
       String prefix = '${element.getEnclosingClass().name.slowToString()}\$';
       if (!name.startsWith(prefix)) {
         // Factory for another interface (that is going away soon).
@@ -120,7 +122,8 @@ void renamePlaceholders(
       name = name.substring(prefix.length);
       result.add(name);
     } else {
-      result.add(renameType(type, renameElement));
+      assert(!placeholder.isRedirectingCall);
+      result.add(renameType(placeholder.type, renameElement));
     }
     return result.toString();
   }
@@ -281,7 +284,7 @@ void renamePlaceholders(
       (Element constructor, List<ConstructorPlaceholder> placeholders) {
         for (ConstructorPlaceholder ph in placeholders) {
           renames[ph.node] =
-              renameConstructor(constructor, ph.type, rename, renameElement);
+              renameConstructor(constructor, ph, rename, renameElement);
         }
   });
   sortedForEach(placeholderCollector.privateNodes, (library, nodes) {