Mountain Lion: use the system download progress.

base/supports_user_data.h

 // 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_SUPPORTS_USER_DATA_H_
 #define BASE_SUPPORTS_USER_DATA_H_
 
 #include <map>
 
 #include "base/base_export.h"
@@ skipping 14 matching lines @@
    public:
     virtual ~Data() {}
   };
 
   // The user data allows the clients to associate data with this object.
   // Multiple user data values can be stored under different keys.
   // This object will TAKE OWNERSHIP of the given data pointer, and will
   // delete the object if it is changed or the object is destroyed.
   Data* GetUserData(const void* key) const;
   void SetUserData(const void* key, Data* data);
+  void RemoveUserData(const void* key);
 
  protected:
   virtual ~SupportsUserData();
 
  private:
   typedef std::map<const void*, linked_ptr<Data> > DataMap;
 
   // Externally-defined data accessible by key
   DataMap user_data_;
 
@@ skipping 16 matching lines @@
 
  private:
   scoped_refptr<T> object_;
 
   DISALLOW_COPY_AND_ASSIGN(UserDataAdapter);
 };
 
 }  // namespace base
 
 #endif  // BASE_SUPPORTS_USER_DATA_H_