DevTools: Do not load css resources content before CSS agent is enabled.

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 402 matching lines @@
 }
 
 void InspectorCSSAgent::enable(ErrorString*, PassRefPtr<EnableCallback> prpCallback)
 {
     m_state->setBoolean(CSSAgentState::cssAgentEnabled, true);
     if (!m_pageAgent->resourceContentLoader()) {
         wasEnabled();
         prpCallback->sendSuccess();
         return;
     }
-    m_pageAgent->resourceContentLoader()->addListener(adoptPtr(new InspectorCSSAgent::InspectorResourceContentLoaderCallback(this, prpCallback)));
+    m_pageAgent->resourceContentLoader()->ensureResourcesContentLoaded(adoptPtr(new InspectorCSSAgent::InspectorResourceContentLoaderCallback(this, prpCallback)));
 }
 
 void InspectorCSSAgent::wasEnabled()
 {
     if (!m_state->getBoolean(CSSAgentState::cssAgentEnabled)) {
         // We were disabled while fetching resources.
         return;
     }
 
     m_instrumentingAgents->setInspectorCSSAgent(this);
@@ skipping 965 matching lines @@
             documentsToChange.add(element->ownerDocument());
     }
 
     m_nodeIdToForcedPseudoState.clear();
     for (HashSet<Document*>::iterator it = documentsToChange.begin(), end = documentsToChange.end(); it != end; ++it)
         (*it)->setNeedsStyleRecalc(SubtreeStyleChange);
 }
 
 } // namespace WebCore