Remove obsolete friend declarations for MSVC.

These friend declarations were added because MSVC had a bug around the
visibility of nested classes. They are no longer necessary.

BUG=617504

Review-Url: https://codereview.chromium.org/2041273002
Cr-Commit-Position: refs/heads/master@{#398255}

third_party/WebKit/Source/platform/PODArena.h

@@ -195,10 +195,6 @@ protected:
     Chunk* m_current;
     size_t m_currentChunkSize;
     Vector<OwnPtr<Chunk>> m_chunks;
-
-#if COMPILER(MSVC)
-    friend struct ::WTF::OwnedPtrDeleter<Chunk>;
-#endif
 };
 
 } // namespace blink

third_party/WebKit/Source/platform/fonts/SimpleFontData.h

@@ -177,9 +177,6 @@ private:
         }
     };
 
-#if COMPILER(MSVC)
-    friend struct ::WTF::OwnedPtrDeleter<DerivedFontData>;
-#endif
     mutable OwnPtr<DerivedFontData> m_derivedFontData;
 
     RefPtr<CustomFontData> m_customFontData;

third_party/WebKit/Source/platform/fonts/shaping/ShapeResult.h

@@ -78,9 +78,6 @@ public:
 
 protected:
     struct RunInfo;
-#if COMPILER(MSVC)
-    friend struct ::WTF::OwnedPtrDeleter<RunInfo>;
-#endif
 
     ShapeResult(const Font*, unsigned numCharacters, TextDirection);
     ShapeResult(const ShapeResult&);

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

@@ -65,9 +65,6 @@ private:
     PaintArtifact m_paintArtifact;
 
     bool m_built;
-
-    // To make MSVC happy.
-    friend struct WTF::OwnedPtrDeleter<DummyRectClient>;
 };
 
 } // namespace blink