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

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index 5de448e994c44c58bd1dff385ebd6ee67c227640..9b1d78fb389d7db4e4d59083b75ab808178e7ab6 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -197,6 +197,7 @@
 #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"
@@ -2574,6 +2575,7 @@ bool Document::dispatchBeforeUnloadEvent(ChromeClient& chromeClient, bool& didAl
 
 void Document::dispatchUnloadEvents()
 {
+    PluginScriptForbiddenScope forbidPluginDestructorScripting;
     RefPtrWillBeRawPtr<Document> protect(this);
     if (m_parser)
         m_parser->stopParsing();