Use explicit HTMLFrameElementBase cast

Source/core/rendering/RenderLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 2162 matching lines @@
     if (view && requiresRepaint)
         renderer()->repaintUsingContainer(repaintContainer, pixelSnappedIntRect(m_repaintRect));
 
     // Schedule the scroll DOM event.
     if (renderer()->node())
         renderer()->node()->document()->eventQueue()->enqueueOrDispatchScrollEvent(renderer()->node(), DocumentEventQueue::ScrollEventElementTarget);
 
     InspectorInstrumentation::didScrollLayer(frame);
 }
 
-static inline bool frameElementAndViewPermitScroll(HTMLFrameElement* frameElement, FrameView* frameView) 
+static inline bool frameElementAndViewPermitScroll(HTMLFrameElementBase* frameElementBase, FrameView* frameView)
 {
     // If scrollbars aren't explicitly forbidden, permit scrolling.
-    if (frameElement && frameElement->scrollingMode() != ScrollbarAlwaysOff)
+    if (frameElementBase && frameElementBase->scrollingMode() != ScrollbarAlwaysOff)
         return true;
 
     // If scrollbars are forbidden, user initiated scrolls should obviously be ignored.
     if (frameView->wasScrolledByUser())
         return false;
 
     // Forbid autoscrolls when scrollbars are off, but permits other programmatic scrolls,
     // like navigation to an anchor.
     Page* page = frameView->frame()->page();
     if (!page)
@@ skipping 35 matching lines @@
             localExposeRect.move(-scrollOffsetDifference);
             newRect = LayoutRect(box->localToAbsoluteQuad(FloatQuad(FloatRect(localExposeRect)), UseTransforms).boundingBox());
         }
     } else if (!parentLayer && renderer()->isBox() && renderBox()->canBeProgramaticallyScrolled()) {
         if (frameView) {
             Element* ownerElement = 0;
             if (renderer()->document())
                 ownerElement = renderer()->document()->ownerElement();
 
             if (ownerElement && ownerElement->renderer()) {
-                HTMLFrameElement* frameElement = 0;
+                HTMLFrameElementBase* frameElementBase = 0;
 
                 if (ownerElement->hasTagName(frameTag) || ownerElement->hasTagName(iframeTag))
-                    frameElement = static_cast<HTMLFrameElement*>(ownerElement);
+                    frameElementBase = static_cast<HTMLFrameElementBase*>(ownerElement);
 
-                if (frameElementAndViewPermitScroll(frameElement, frameView)) {
+                if (frameElementAndViewPermitScroll(frameElementBase, frameView)) {
                     LayoutRect viewRect = frameView->visibleContentRect();
                     LayoutRect exposeRect = getRectToExpose(viewRect, rect, alignX, alignY);
 
                     int xOffset = roundToInt(exposeRect.x());
                     int yOffset = roundToInt(exposeRect.y());
                     // Adjust offsets if they're outside of the allowable range.
                     xOffset = max(0, min(frameView->contentsWidth(), xOffset));
                     yOffset = max(0, min(frameView->contentsHeight(), yOffset));
 
                     frameView->setScrollPosition(IntPoint(xOffset, yOffset));
@@ skipping 4108 matching lines @@
     }
 }
 
 void showLayerTree(const WebCore::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif