Remove Document::LoadEventTried, it's not necessary

Source/core/dom/Document.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 872 matching lines @@
     void initSecurityContext(const DocumentInit&);
     void initContentSecurityPolicy(const ContentSecurityPolicyResponseHeaders&);
 
     bool allowInlineEventHandlers(Node*, EventListener*, const String& contextURL, const WTF::OrdinalNumber& contextLine);
     bool allowExecutingScripts(Node*);
 
     void statePopped(PassRefPtr<SerializedScriptValue>);
 
     enum LoadEventProgress {
         LoadEventNotRun,
-        LoadEventTried,
         LoadEventInProgress,
         LoadEventCompleted,
         BeforeUnloadEventInProgress,
         BeforeUnloadEventCompleted,
         PageHideInProgress,
         UnloadEventInProgress,
         UnloadEventHandled
     };
     bool loadEventStillNeeded() const { return m_loadEventProgress == LoadEventNotRun; }
     bool processingLoadEvent() const { return m_loadEventProgress == LoadEventInProgress; }
@@ skipping 510 matching lines @@
 Node* eventTargetNodeForDocument(Document*);
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLiveDocumentInstances();
 #endif
 
 #endif // Document_h