Inspector: replace generic discardAgents logic with explicit call to discard a listener.

Source/core/inspector/InspectorCSSAgent.cpp

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 677 matching lines @@
     , m_domAgent(domAgent)
     , m_pageAgent(pageAgent)
     , m_lastStyleSheetId(1)
     , m_creatingViaInspectorStyleSheet(false)
 {
     m_domAgent->setDOMListener(this);
 }
 
 InspectorCSSAgent::~InspectorCSSAgent()
 {
-    ASSERT(!m_domAgent);
+    if (m_domAgent)
+        m_domAgent->setDOMListener(0);
     reset();
 }
 
 void InspectorCSSAgent::setFrontend(InspectorFrontend* frontend)
 {
     ASSERT(!m_frontend);
     m_frontend = frontend->css();
 }
 
 void InspectorCSSAgent::clearFrontend()
 {
     ASSERT(m_frontend);
     m_frontend = 0;
     resetNonPersistentData();
     stopSelectorProfilerImpl(0, false);
 }
 
-void InspectorCSSAgent::discardAgent()
-{
-    m_domAgent->setDOMListener(0);
-    m_domAgent = 0;
-}
-
 void InspectorCSSAgent::restore()
 {
     if (m_state->getBoolean(CSSAgentState::cssAgentEnabled)) {
         ErrorString error;
         enable(&error);
     }
     if (m_state->getBoolean(CSSAgentState::isSelectorProfiling)) {
         String errorString;
         startSelectorProfiler(&errorString);
     }
@@ skipping 813 matching lines @@
     if (!element)
         return;
 
     NodeToInspectorStyleSheet::iterator it = m_nodeToInspectorStyleSheet.find(element);
     if (it == m_nodeToInspectorStyleSheet.end())
         return;
 
     it->value->didModifyElementAttribute();
 }
 
+void InspectorCSSAgent::willDestroyDOMAgent()
+{
+    m_domAgent = 0;
+}
+
 void InspectorCSSAgent::styleSheetChanged(InspectorStyleSheet* styleSheet)
 {
     if (m_frontend)
         m_frontend->styleSheetChanged(styleSheet->id());
 }
 
 void InspectorCSSAgent::resetPseudoStates()
 {
     HashSet<Document*> documentsToChange;
     for (NodeIdToForcedPseudoState::iterator it = m_nodeIdToForcedPseudoState.begin(), end = m_nodeIdToForcedPseudoState.end(); it != end; ++it) {
         Element* element = toElement(m_domAgent->nodeForId(it->key));
         if (element && element->ownerDocument())
             documentsToChange.add(element->ownerDocument());
     }
 
     m_nodeIdToForcedPseudoState.clear();
     for (HashSet<Document*>::iterator it = documentsToChange.begin(), end = documentsToChange.end(); it != end; ++it)
         (*it)->styleResolverChanged(RecalcStyleImmediately);
 }
 
 } // namespace WebCore