Add 'toString' method to NativeBehavior

pkg/compiler/lib/src/native/behavior.dart

 // Copyright (c) 2014, 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.
 
 part of native;
 
 /// This class is a temporary work-around until we get a more powerful DartType.
 class SpecialType {
-final String name;
-const SpecialType._(this.name);
+  final String name;
+  const SpecialType._(this.name);
 
-/// The type Object, but no subtypes:
-static const JsObject = const SpecialType._('=Object');
+  /// The type Object, but no subtypes:
+  static const JsObject = const SpecialType._('=Object');
 
-int get hashCode => name.hashCode;
+  int get hashCode => name.hashCode;
 }
 
 /**
  * A summary of the behavior of a native element.
  *
  * Native code can return values of one type and cause native subtypes of
  * another type to be instantiated.  By default, we compute both from the
  * declared type.
  *
  * A field might yield any native type that 'is' the field type.
@@ skipping 26 matching lines @@
 
   /// [DartType]s or [SpecialType]s instantiated by the native element.
   final List typesInstantiated = [];
 
   // If this behavior is for a JS expression, [codeTemplate] contains the
   // parsed tree.
   js.Template codeTemplate;
 
   final SideEffects sideEffects = new SideEffects.empty();
 
+  String toString() {
+    return 'NativeBehavior(returns: ${typesReturned}, '
+        'creates: ${typesInstantiated}, '
+        'sideEffects: ${sideEffects})';
+  }
+
+
   /// Processes the type specification string of a call to JS and stores the
   /// result in the [typesReturned] and [typesInstantiated]. It furthermore
   /// computes the side effects, and, if given, invokes [setSideEffects] with
   /// the computed effects. If no side effects are encoded in the [specString]
   /// the [setSideEffects] method is not invoked.
   ///
   /// Two forms of the string is supported:
   /// 1) A single type string of the form 'void', '', 'var' or 'T1|...|Tn'
   ///    which defines the types returned and for the later form also created by
   ///    the call to JS.
@@ skipping 467 matching lines @@
         _errorNode(locationNodeOrElement, compiler),
         "Type '$typeString' not found.");
     return null;
   }
 
   static _errorNode(locationNodeOrElement, compiler) {
     if (locationNodeOrElement is Node) return locationNodeOrElement;
     return locationNodeOrElement.parseNode(compiler);
   }
 }