Make classes and structures in web fast-allocated.

Source/web/LinkHighlightImpl.h

Index: Source/web/LinkHighlightImpl.h
diff --git a/Source/web/LinkHighlightImpl.h b/Source/web/LinkHighlightImpl.h
index fe34daef6ec544f5809129f6b215556429ffeee9..187ca5aa41613e5bfc2253a09bc47806ac59b8eb 100644
--- a/Source/web/LinkHighlightImpl.h
+++ b/Source/web/LinkHighlightImpl.h
@@ -50,6 +50,7 @@ class LinkHighlightImpl final : public LinkHighlight
     , public WebContentLayerClient
     , public WebCompositorAnimationDelegate
     , public WebCompositorAnimationPlayerClient {
+    WTF_MAKE_FAST_ALLOCATED(LinkHighlightImpl);
 public:
     static PassOwnPtr<LinkHighlightImpl> create(Node*, WebViewImpl*);
     ~LinkHighlightImpl() override;