Minor fix for base::Bind documentation

base/callback.h

 // This file was GENERATED by command:
 //     pump.py callback.h.pump
 // DO NOT EDIT BY HAND!!!
 
 
 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_CALLBACK_H_
@@ skipping 105 matching lines @@
 //   pointer.
 //
 //   base::Closure cb = base::Bind(&MyClass::MyFunc, this, 23, "hello world");
 //
 // PARTIAL BINDING OF PARAMETERS
 //
 //   You can specify some parameters when you create the callback, and specify
 //   the rest when you execute the callback.
 //
 //   void MyFunc(int i, const std::string& str) {}
-//   base::Callback<void(int)> cb = base::Bind(&MyFunc, 23);
+//   base::Callback<void(const std::string)> cb = base::Bind(&MyFunc, 23);
 //   cb.Run("hello world");
 //
 //   When calling a function bound parameters are first, followed by unbound
 //   parameters.
 //
 //
 // -----------------------------------------------------------------------------
 // Quick reference for advanced binding
 // -----------------------------------------------------------------------------
 //
@@ skipping 604 matching lines @@
 };
 
 
 // Syntactic sugar to make Callbacks<void(void)> easier to declare since it
 // will be used in a lot of APIs with delayed execution.
 typedef Callback<void(void)> Closure;
 
 }  // namespace base
 
 #endif  // BASE_CALLBACK_H