Simplify ContextLifecycleNotifier's handling of ActiveDOMObjects.

Source/core/dom/ExecutionContext.cpp

Index: Source/core/dom/ExecutionContext.cpp
diff --git a/Source/core/dom/ExecutionContext.cpp b/Source/core/dom/ExecutionContext.cpp
index ebce1cbfad2653c1989e289108dfe396d7fbed56..5abde3878489ee2166a8fe0a3988a17fbe8b2a69 100644
--- a/Source/core/dom/ExecutionContext.cpp
+++ b/Source/core/dom/ExecutionContext.cpp
@@ -100,11 +100,6 @@ void ExecutionContext::stopActiveDOMObjects()
     notifyStoppingActiveDOMObjects();
 }
 
-unsigned ExecutionContext::activeDOMObjectCount()
-{
-    return activeDOMObjects().size();
-}
-
 void ExecutionContext::suspendScheduledTasks()
 {
     suspendActiveDOMObjects();