Revert of Refactor ScrollableArea::setScrollPosition.

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

Index: third_party/WebKit/Source/core/page/SpatialNavigation.cpp
diff --git a/third_party/WebKit/Source/core/page/SpatialNavigation.cpp b/third_party/WebKit/Source/core/page/SpatialNavigation.cpp
index fae5f8e406daf2473e5a23f09f86e10a36d09981..d329451a9c3e691c055bd49ed5a02226e34c07df 100644
--- a/third_party/WebKit/Source/core/page/SpatialNavigation.cpp
+++ b/third_party/WebKit/Source/core/page/SpatialNavigation.cpp
@@ -244,22 +244,32 @@
         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();