Add removeAll method to sets and maps and use them

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 1836 matching lines @@
     Vector<RenderWidget*> overlappedRequestClients;
     OverlapTestRequestMap::iterator end = overlapTestRequests.end();
     LayoutRect boundingBox = layer->physicalBoundingBox(rootLayer);
     for (OverlapTestRequestMap::iterator it = overlapTestRequests.begin(); it != end; ++it) {
         if (!boundingBox.intersects(it->value))
             continue;
 
         it->key->setIsOverlapped(true);
         overlappedRequestClients.append(it->key);
     }
-    for (size_t i = 0; i < overlappedRequestClients.size(); ++i)
-        overlapTestRequests.remove(overlappedRequestClients[i]);
+    overlapTestRequests.removeAll(overlappedRequestClients);
 }
 
 static bool shouldDoSoftwarePaint(const RenderLayer* layer, bool paintingReflection)
 {
     return paintingReflection && !layer->has3DTransform();
 }
 
 static inline bool shouldSuppressPaintingLayer(RenderLayer* layer)
 {
     // Avoid painting descendants of the root layer when stylesheets haven't loaded. This eliminates FOUC.
@@ skipping 2139 matching lines @@
     }
 }
 
 void showLayerTree(const WebCore::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif