Remove obsolete friend declarations for MSVC.

third_party/WebKit/Source/platform/PODArena.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 177 matching lines @@
         Allocator* m_allocator;
         uint8_t* m_base;
         size_t m_size;
         size_t m_currentOffset;
     };
 
     RefPtr<Allocator> m_allocator;
     Chunk* m_current;
     size_t m_currentChunkSize;
     Vector<OwnPtr<Chunk>> m_chunks;
-
-#if COMPILER(MSVC)
-    friend struct ::WTF::OwnedPtrDeleter<Chunk>;
-#endif
 };
 
 } // namespace blink
 
 #endif // PODArena_h