Remove backends.

compiler/java/com/google/dart/compiler/ast/viz/DotWriter.java

Index: compiler/java/com/google/dart/compiler/ast/viz/DotWriter.java
diff --git a/compiler/java/com/google/dart/compiler/ast/viz/DotWriter.java b/compiler/java/com/google/dart/compiler/ast/viz/DotWriter.java
index 9a4fa71e96c23fe40bd77c431dd181364f00f8a0..b0ad21504da9089ae43f161d03ce7d1751fbebd3 100644
--- a/compiler/java/com/google/dart/compiler/ast/viz/DotWriter.java
+++ b/compiler/java/com/google/dart/compiler/ast/viz/DotWriter.java
@@ -1,4 +1,4 @@
-// Copyright (c) 2011, the Dart project authors. Please see the AUTHORS file
+// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
@@ -110,10 +110,6 @@ public class DotWriter extends BaseASTWriter {
       style.append(", color=blue");
     }
     
-    if(node.isInstrumentedNode()){
-      style.append(", style=filled, fillcolor=yellow");
-    }
-    
     return style.toString();
   }