Remove obsolete friend declarations for MSVC.

third_party/WebKit/Source/platform/testing/TestPaintArtifact.h

 // Copyright 2016 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 TestPaintArtifact_h
 #define TestPaintArtifact_h
 
 #include "base/memory/ref_counted.h"
 #include "platform/graphics/Color.h"
 #include "platform/graphics/paint/DisplayItemList.h"
@@ skipping 47 matching lines @@
     Vector<OwnPtr<DummyRectClient>> m_dummyClients;
 
     // Exists if m_built is false.
     DisplayItemList m_displayItemList;
     Vector<PaintChunk> m_paintChunks;
 
     // Exists if m_built is true.
     PaintArtifact m_paintArtifact;
 
     bool m_built;
-
-    // To make MSVC happy.
-    friend struct WTF::OwnedPtrDeleter<DummyRectClient>;
 };
 
 } // namespace blink
 
 #endif // TestPaintArtifact_h