[dart2dart] Optionally cut types in variable declarations:

lib/compiler/implementation/dart_backend/backend.dart

Index: lib/compiler/implementation/dart_backend/backend.dart
diff --git a/lib/compiler/implementation/dart_backend/backend.dart b/lib/compiler/implementation/dart_backend/backend.dart
index 082fd898cc9b3afdef183abed5c2d7dc4cb9be83..128e4e03d6b569776656524976ab07c191e1ccfb 100644
--- a/lib/compiler/implementation/dart_backend/backend.dart
+++ b/lib/compiler/implementation/dart_backend/backend.dart
@@ -5,12 +5,13 @@
 class DartBackend extends Backend {
   final List<CompilerTask> tasks;
   final bool minify;
+  final bool cutDeclarationTypes;
 
   Map<Element, TreeElements> get resolvedElements =>
       compiler.enqueuer.resolution.resolvedElements;
 
   DartBackend(Compiler compiler, this.minify)
-      : tasks = <CompilerTask>[],
+      : tasks = <CompilerTask>[], cutDeclarationTypes = false,
       super(compiler);
 
   void enqueueHelpers(Enqueuer world) { }
@@ -102,7 +103,8 @@ class DartBackend extends Backend {
     // Create renames.
     Map<Node, String> renames = new Map<Node, String>();
     Map<LibraryElement, String> imports = new Map<LibraryElement, String>();
-    renamePlaceholders(compiler, collector, renames, imports, minify);
+    renamePlaceholders(
+        compiler, collector, renames, imports, minify, cutDeclarationTypes);
 
     // Sort elements.
     final sortedTopLevels = sortElements(topLevelElements);