Remove printDebugInfo from Unparser

lib/compiler/implementation/tree/unparser.dart

Index: lib/compiler/implementation/tree/unparser.dart
diff --git a/lib/compiler/implementation/tree/unparser.dart b/lib/compiler/implementation/tree/unparser.dart
index fa19630a860ee9e590921410978c94d96d0c65a7..6757667e31498f3abe321fe96d4d0c1aba0eac38 100644
--- a/lib/compiler/implementation/tree/unparser.dart
+++ b/lib/compiler/implementation/tree/unparser.dart
@@ -4,9 +4,8 @@
 
 class Unparser implements Visitor {
   StringBuffer sb;
-  final bool printDebugInfo;
 
-  Unparser([this.printDebugInfo = false]);
+  Unparser();
 
   String unparse(Node node) {
     sb = new StringBuffer();
@@ -19,13 +18,7 @@ class Unparser implements Visitor {
   }
 
   visit(Node node) {
-    if (node !== null) {
-      if (printDebugInfo) sb.add('[${node.getObjectDescription()}: ');
-      node.accept(this);
-      if (printDebugInfo) sb.add(']');
-    } else if (printDebugInfo) {
-      sb.add('[null]');
-    }
+    if (node !== null) node.accept(this);
   }
 
   visitBlock(Block node) {