Remove special wheel handling path from ScrollableArea

Source/core/frame/FrameView.h

Index: Source/core/frame/FrameView.h
diff --git a/Source/core/frame/FrameView.h b/Source/core/frame/FrameView.h
index a8bb967ccd28eda6f44ecbb7bee578e7afa13204..31ffd187be7ed575bc2ae68d8ba614403a38d339 100644
--- a/Source/core/frame/FrameView.h
+++ b/Source/core/frame/FrameView.h
@@ -307,11 +307,6 @@ public:
     void removeResizerArea(LayoutBox&);
     const ResizerAreaSet* resizerAreas() const { return m_resizerAreas.get(); }
 
-    // This function exists for ports that need to handle wheel events manually.
-    // On Mac WebKit1 the underlying NSScrollView just does the scrolling, but on most other platforms
-    // we need this function in order to do the scroll ourselves.
-    ScrollResult wheelEvent(const PlatformWheelEvent&);
-
     bool shouldUseIntegerScrollOffset() const override;
 
     bool isActive() const override;