Revert of [debugger] flood function for stepping before calling it.

src/js/collection.js

 // Copyright 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";
 
 %CheckIsBootstrapping();
 
 // -------------------------------------------------------------------
@@ skipping 230 matching lines @@
 function SetForEach(f, receiver) {
   if (!IS_SET(this)) {
     throw MakeTypeError(kIncompatibleMethodReceiver,
                         'Set.prototype.forEach', this);
   }
 
   if (!IS_CALLABLE(f)) throw MakeTypeError(kCalledNonCallable, f);
 
   var iterator = new SetIterator(this, ITERATOR_KIND_VALUES);
   var key;
+  var stepping = DEBUG_IS_STEPPING(f);
   var value_array = [UNDEFINED];
   while (%SetIteratorNext(iterator, value_array)) {
+    if (stepping) %DebugPrepareStepInIfStepping(f);
     key = value_array[0];
     %_Call(f, receiver, key, key, this);
   }
 }
 
 // -------------------------------------------------------------------
 
 %SetCode(GlobalSet, SetConstructor);
 %FunctionSetLength(GlobalSet, 0);
 %FunctionSetPrototype(GlobalSet, new GlobalObject());
@@ skipping 159 matching lines @@
 
 function MapForEach(f, receiver) {
   if (!IS_MAP(this)) {
     throw MakeTypeError(kIncompatibleMethodReceiver,
                         'Map.prototype.forEach', this);
   }
 
   if (!IS_CALLABLE(f)) throw MakeTypeError(kCalledNonCallable, f);
 
   var iterator = new MapIterator(this, ITERATOR_KIND_ENTRIES);
+  var stepping = DEBUG_IS_STEPPING(f);
   var value_array = [UNDEFINED, UNDEFINED];
   while (%MapIteratorNext(iterator, value_array)) {
+    if (stepping) %DebugPrepareStepInIfStepping(f);
     %_Call(f, receiver, value_array[1], value_array[0], this);
   }
 }
 
 // -------------------------------------------------------------------
 
 %SetCode(GlobalMap, MapConstructor);
 %FunctionSetLength(GlobalMap, 0);
 %FunctionSetPrototype(GlobalMap, new GlobalObject());
 %AddNamedProperty(GlobalMap.prototype, "constructor", GlobalMap, DONT_ENUM);
@@ skipping 25 matching lines @@
   "set_has", SetHas,
   "set_delete", SetDelete,
 ]);
 
 utils.Export(function(to) {
   to.GetExistingHash = GetExistingHash;
   to.GetHash = GetHash;
 });
 
 })