Removed main-thread one dimensional scrolling paths.

third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.h

 /*
  * Copyright (C) 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 73 matching lines @@
     RetainPtr<BlinkScrollbarPainterDelegate> m_verticalScrollbarPainterDelegate;
 
     void initialScrollbarPaintTask();
     OwnPtr<CancellableTaskFactory> m_initialScrollbarPaintTaskFactory;
 
     void sendContentAreaScrolledTask();
     OwnPtr<CancellableTaskFactory> m_sendContentAreaScrolledTaskFactory;
     OwnPtr<WebTaskRunner> m_taskRunner;
     FloatSize m_contentAreaScrolledTimerScrollDelta;
 
-    ScrollResultOneDimensional userScroll(ScrollbarOrientation, ScrollGranularity, float delta) override;
+    ScrollResult userScroll(ScrollGranularity, const FloatSize& delta) override;
     void scrollToOffsetWithoutAnimation(const FloatPoint&) override;
 
     void handleWheelEventPhase(PlatformWheelEventPhase) override;
 
     void cancelAnimation() override;
 
     void contentAreaWillPaint() const override;
     void mouseEnteredContentArea() const override;
     void mouseExitedContentArea() const override;
     void mouseMovedInContentArea() const override;
@@ skipping 26 matching lines @@
     void immediateScrollTo(const FloatPoint&);
 
     bool m_haveScrolledSincePageLoad;
     bool m_needsScrollerStyleUpdate;
     IntRect m_visibleScrollerThumbRect;
 };
 
 } // namespace blink
 
 #endif // ScrollAnimatorMac_h