Disable implicit conversion of scoped_refptr<T> to T* on Windows.

base/win/scoped_comptr.h

 // Copyright (c) 2011 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_WIN_SCOPED_COMPTR_H_
 #define BASE_WIN_SCOPED_COMPTR_H_
 
 #include <unknwn.h>
 
 #include "base/logging.h"
@@ skipping 115 matching lines @@
 
     if (!other || !ptr_)
       return false;
 
     ScopedComPtr<IUnknown> my_identity;
     QueryInterface(my_identity.Receive());
 
     ScopedComPtr<IUnknown> other_identity;
     other->QueryInterface(other_identity.Receive());
 
-    return static_cast<IUnknown*>(my_identity) ==
-           static_cast<IUnknown*>(other_identity);
+    return my_identity == other_identity;
   }
 
   // Provides direct access to the interface.
   // Here we use a well known trick to make sure we block access to
   // IUnknown methods so that something bad like this doesn't happen:
   //    ScopedComPtr<IUnknown> p(Foo());
   //    p->Release();
   //    ... later the destructor runs, which will Release() again.
   // and to get the benefit of the DCHECKs we add to QueryInterface.
   // There's still a way to call these methods if you absolutely must
@@ skipping 11 matching lines @@
 
   static const IID& iid() {
     return *interface_id;
   }
 };
 
 }  // namespace win
 }  // namespace base
 
 #endif  // BASE_WIN_SCOPED_COMPTR_H_