[V8] Unify get function name for debugging purpose

src/debug/mirrors.js

 // Copyright 2006-2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 (function(global, utils) {
 "use strict";
 
 // ----------------------------------------------------------------------------
 // Imports
 
@@ skipping 969 matching lines @@
 /**
  * Returns the name of the function.
  * @return {string} Name of the function
  */
 FunctionMirror.prototype.name = function() {
   return %FunctionGetName(this.value_);
 };
 
 
 /**
+ * Returns the displayName if it is set, otherwise name, otherwise inferred
+ * name.
+ * @return {string} Name of the function
+ */
+FunctionMirror.prototype.debugName = function() {
+  return %FunctionGetDebugName(this.value_);
+}
+
+
+/**
  * Returns the inferred name of the function.
  * @return {string} Name of the function
  */
 FunctionMirror.prototype.inferredName = function() {
   return %FunctionGetInferredName(this.value_);
 };
 
 
 /**
  * Returns the source code for the function.
@@ skipping 2122 matching lines @@
 // Functions needed by the debugger runtime.
 utils.InstallFunctions(utils, DONT_ENUM, [
   "ClearMirrorCache", ClearMirrorCache
 ]);
 
 // Export to debug.js
 utils.Export(function(to) {
   to.MirrorType = MirrorType;
 });
 })