Simpler return value of HashTable::add/HashMap:add and others

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 3965 matching lines @@
             // (eg. for border / scroll bars) and if it's composited then the entire contents
             // as well as they may be on another composited layer. Skip reporting contents
             // for non-composited layers as they'll get projected to the same layer as the
             // bounding box.
             if (compositingState() != NotComposited)
                 rect.append(m_scrollableArea->overflowRect());
 
             rects.set(this, rect);
             if (const RenderLayer* parentLayer = parent()) {
                 LayerHitTestRects::iterator iter = rects.find(parentLayer);
-                if (iter == rects.end())
-                    iter = rects.add(parentLayer, Vector<LayoutRect>()).iterator;
-                iter->value.append(boundingBox(parentLayer));
+                if (iter == rects.end()) {
+                    rects.add(parentLayer, Vector<LayoutRect>()).storedValue->value.append(boundingBox(parentLayer));
+                } else {
+                    iter->value.append(boundingBox(parentLayer));
+                }
             }
         } else {
             rect.append(localBoundingBox());
             rects.set(this, rect);
         }
     }
 }
 
 DisableCompositingQueryAsserts::DisableCompositingQueryAsserts()
     : m_disabler(gCompositingQueryMode, CompositingQueriesAreAllowed) { }
@@ skipping 12 matching lines @@
     }
 }
 
 void showLayerTree(const WebCore::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif