Made PinchViewport a ScrollableArea

Source/platform/scroll/ScrollView.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 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 1094 matching lines @@
     if (scrollOrigin() == origin)
         return;
 
     ScrollableArea::setScrollOrigin(origin);
 
     // Update if the scroll origin changes, since our position will be different if the content size did not change.
     if (updatePositionAtAll && updatePositionSynchronously)
         updateScrollbars(scrollOffset());
 }
 
-int ScrollView::pageStep(ScrollbarOrientation orientation) const
-{
-    int length = (orientation == HorizontalScrollbar) ? visibleWidth() : visibleHeight();
-    int minPageStep = static_cast<float>(length) * minFractionToStepWhenPaging();
-    int pageStep = std::max(minPageStep, length - maxOverlapBetweenPages());
-
-    return std::max(pageStep, 1);
-}
-
 } // namespace WebCore