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/2043633002
Cr-Commit-Position: refs/heads/master@{#398181}

third_party/WebKit/Source/platform/graphics/ContiguousContainer.h

@@ -70,9 +70,6 @@ private:
     Vector<OwnPtr<Buffer>> m_buffers;
     unsigned m_endIndex;
     size_t m_maxObjectSize;
-
-    // Makes Buffer accessible when clearing m_buffers. Fixes MSVC build.
-    friend struct WTF::OwnedPtrDeleter<Buffer>;
 };
 
 // For most cases, no alignment stricter than pointer alignment is required. If

third_party/WebKit/Source/platform/graphics/ImageDecodingStore.h

@@ -217,11 +217,6 @@ private:
     // This mutex also protects calls to underlying skBitmap's
     // lockPixels()/unlockPixels() as they are not threadsafe.
     Mutex m_mutex;
-
-#if COMPILER(MSVC)
-    friend struct ::WTF::OwnedPtrDeleter<CacheEntry>;
-    friend struct ::WTF::OwnedPtrDeleter<DecoderCacheEntry>;
-#endif
 };
 
 } // namespace blink

third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.h

@@ -58,9 +58,6 @@ private:
     scoped_refptr<cc::Layer> m_rootLayer;
     OwnPtr<WebLayer> m_webLayer;
     Vector<OwnPtr<ContentLayerClientImpl>> m_contentLayerClients;
-
-    // For ~PaintArtifactCompositor on MSVC.
-    friend struct WTF::OwnedPtrDeleter<ContentLayerClientImpl>;
 };
 
 } // namespace blink