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

Source/core/frame/LocalFrame.cpp

Index: Source/core/frame/LocalFrame.cpp
diff --git a/Source/core/frame/LocalFrame.cpp b/Source/core/frame/LocalFrame.cpp
index b44f18ae23f8d902b07023877479e0e457519d33..22e07c9be0174e5bf295af218e85d8862a500f40 100644
--- a/Source/core/frame/LocalFrame.cpp
+++ b/Source/core/frame/LocalFrame.cpp
@@ -65,6 +65,7 @@
 #include "core/paint/TransformRecorder.h"
 #include "core/svg/SVGDocumentExtensions.h"
 #include "platform/DragImage.h"
+#include "platform/PluginScriptForbiddenScope.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/ScriptForbiddenScope.h"
 #include "platform/graphics/GraphicsContext.h"
@@ -274,6 +275,7 @@ void LocalFrame::reload(FrameLoadType loadType, ClientRedirectPolicy clientRedir
 
 void LocalFrame::detach()
 {
+    PluginScriptForbiddenScope forbidPluginDestructorScripting;
     // A lot of the following steps can result in the current frame being
     // detached, so protect a reference to it.
     RefPtrWillBeRawPtr<LocalFrame> protect(this);