Add a scoping object to help block scripting during plugin destruction.

Source/core/dom/Document.cpp

 /*
  * 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, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 179 matching lines @@
 #include "core/svg/SVGDocumentExtensions.h"
 #include "core/svg/SVGTitleElement.h"
 #include "core/svg/SVGUseElement.h"
 #include "core/workers/SharedWorkerRepositoryClient.h"
 #include "core/xml/parser/XMLDocumentParser.h"
 #include "platform/DateComponents.h"
 #include "platform/EventDispatchForbiddenScope.h"
 #include "platform/Language.h"
 #include "platform/LengthFunctions.h"
 #include "platform/Logging.h"
+#include "platform/PluginScriptForbiddenScope.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/ScriptForbiddenScope.h"
 #include "platform/TraceEvent.h"
 #include "platform/network/ContentSecurityPolicyParsers.h"
 #include "platform/network/HTTPParsers.h"
 #include "platform/scroll/ScrollbarTheme.h"
 #include "platform/text/PlatformLocale.h"
 #include "platform/text/SegmentedString.h"
 #include "platform/weborigin/OriginAccessEntry.h"
 #include "platform/weborigin/SchemeRegistry.h"
@@ skipping 2357 matching lines @@
     String text = beforeUnloadEvent->returnValue();
     if (chromeClient.openBeforeUnloadConfirmPanel(text, m_frame)) {
         didAllowNavigation = true;
         return true;
     }
     return false;
 }
 
 void Document::dispatchUnloadEvents()
 {
+    PluginScriptForbiddenScope forbidPluginDestructorScripting;
     RefPtrWillBeRawPtr<Document> protect(this);
     if (m_parser)
         m_parser->stopParsing();
 
     if (m_loadEventProgress == LoadEventNotRun)
         return;
 
     if (m_loadEventProgress <= UnloadEventInProgress) {
         Element* currentFocusedElement = focusedElement();
         if (isHTMLInputElement(currentFocusedElement))
@@ skipping 3123 matching lines @@
 #ifndef NDEBUG
 using namespace blink;
 void showLiveDocumentInstances()
 {
     WeakDocumentSet& set = liveDocumentSet();
     fprintf(stderr, "There are %u documents currently alive:\n", set.size());
     for (Document* document : set)
         fprintf(stderr, "- Document %p URL: %s\n", document, document->url().string().utf8().data());
 }
 #endif