Revert of Refactor ScrollableArea::setScrollPosition.

third_party/WebKit/Source/core/page/SpatialNavigation.cpp

 /*
  * Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Antonio Gomes <tonikitoo@webkit.org>
  *
  * 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
@@ skipping 226 matching lines @@
 
   if (canScrollInDirection(container, type)) {
     int dx = 0;
     int dy = 0;
     // TODO(leviw): Why are these values truncated (toInt) instead of rounding?
     FrameView* frameView = container->document().view();
     int pixelsPerLineStep = ScrollableArea::pixelsPerLineStep(
         frameView ? frameView->getHostWindow() : nullptr);
     switch (type) {
       case WebFocusTypeLeft:
-        dx = -pixelsPerLineStep;
+        dx = -std::min(pixelsPerLineStep,
+                       container->layoutBox()->scrollLeft().toInt());
         break;
       case WebFocusTypeRight:
         ASSERT(container->layoutBox()->scrollWidth() >
                (container->layoutBox()->scrollLeft() +
                 container->layoutBox()->clientWidth()));
-        dx = pixelsPerLineStep;
+        dx = std::min(pixelsPerLineStep,
+                      (container->layoutBox()->scrollWidth() -
+                       (container->layoutBox()->scrollLeft() +
+                        container->layoutBox()->clientWidth()))
+                          .toInt());
         break;
       case WebFocusTypeUp:
-        dy = -pixelsPerLineStep;
+        dy = -std::min(pixelsPerLineStep,
+                       container->layoutBox()->scrollTop().toInt());
         break;
       case WebFocusTypeDown:
         ASSERT(container->layoutBox()->scrollHeight() -
                (container->layoutBox()->scrollTop() +
                 container->layoutBox()->clientHeight()));
-        dy = pixelsPerLineStep;
+        dy = std::min(pixelsPerLineStep,
+                      (container->layoutBox()->scrollHeight() -
+                       (container->layoutBox()->scrollTop() +
+                        container->layoutBox()->clientHeight()))
+                          .toInt());
         break;
       default:
         ASSERT_NOT_REACHED();
         return false;
     }
 
     container->layoutBox()->scrollByRecursively(IntSize(dx, dy));
     return true;
   }
 
@@ skipping 407 matching lines @@
   return rect;
 }
 
 HTMLFrameOwnerElement* frameOwnerElement(FocusCandidate& candidate) {
   return candidate.isFrameOwnerElement()
              ? toHTMLFrameOwnerElement(candidate.visibleNode)
              : nullptr;
 };
 
 }  // namespace blink