Removed main-thread one dimensional scrolling paths.

third_party/WebKit/Source/core/layout/api/LayoutBoxItem.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef LayoutBoxItem_h
 #define LayoutBoxItem_h
 
 #include "core/layout/LayoutBox.h"
 #include "core/layout/api/LayoutBoxModel.h"
 #include "platform/scroll/ScrollTypes.h"
@@ skipping 15 matching lines @@
 
     explicit LayoutBoxItem(std::nullptr_t) : LayoutBoxModel(nullptr) { }
 
     LayoutBoxItem() { }
 
     LayoutBoxItem enclosingBox() const
     {
         return LayoutBoxItem(toBox()->enclosingBox());
     }
 
-    ScrollResultOneDimensional scroll(ScrollDirectionPhysical direction, ScrollGranularity granularity, float delta = 1)
+    ScrollResult scroll(ScrollGranularity granularity, const FloatSize& delta)
     {
-        return toBox()->scroll(direction, granularity, delta);
+        return toBox()->scroll(granularity, delta);
     }
 
 private:
     LayoutBox* toBox()
     {
         return toLayoutBox(layoutObject());
     }
 
     const LayoutBox* toBox() const
     {
         return toLayoutBox(layoutObject());
     }
 };
 
 } // namespace blink
 
 #endif // LayoutBoxItem_h