Add removeAll method to sets and maps and use them

Source/core/fetch/ResourceLoadPriorityOptimizer.cpp

Index: Source/core/fetch/ResourceLoadPriorityOptimizer.cpp
diff --git a/Source/core/fetch/ResourceLoadPriorityOptimizer.cpp b/Source/core/fetch/ResourceLoadPriorityOptimizer.cpp
index e4a0fc7d38886df07450e5c26c4a9fe256813963..776f7f2d2c9ef579b43f3882ff996a603e4fccdb 100644
--- a/Source/core/fetch/ResourceLoadPriorityOptimizer.cpp
+++ b/Source/core/fetch/ResourceLoadPriorityOptimizer.cpp
@@ -86,9 +86,7 @@ void ResourceLoadPriorityOptimizer::updateAllImageResourcePriorities()
             objectsToRemove.append(obj);
         }
     }
-
-    for (Vector<RenderObject*>::iterator it = objectsToRemove.begin(); it != objectsToRemove.end(); ++it)
-        m_objects.remove(*it);
+    m_objects.removeAll(objectsToRemove);
 
     updateImageResourcesWithLoadPriority();
 }