Fix leak bug 87040 (and related assertions) by noting that nsImageBoxFrame is a leaf so we shouldn't try to give it children that get dropped on the floor and leak other things that they own. r=waterson, pavlov sr=hyatt

layout/base/nsCSSFrameConstructor.cpp

@@ -5509,7 +5509,6 @@ nsCSSFrameConstructor::ConstructXULFrame(nsIPresShell*            aPresShell,
       } // End of RESIZER CONSTRUCTION logic
 
       else if (aTag == nsXULAtoms::image) {
-        processChildren = PR_TRUE;
         isReplaced = PR_TRUE;
         rv = NS_NewImageBoxFrame(aPresShell, &newFrame);
       }