Block scripting in plugin teardown during Document unload.

content/renderer/pepper/pepper_plugin_instance_impl.cc

Index: content/renderer/pepper/pepper_plugin_instance_impl.cc
diff --git a/content/renderer/pepper/pepper_plugin_instance_impl.cc b/content/renderer/pepper/pepper_plugin_instance_impl.cc
index 85449bacf5bb1da057bc660f59ce8d98df8acedc..a5662bcebea43a4beef5da37f47b36ad03b8b13f 100644
--- a/content/renderer/pepper/pepper_plugin_instance_impl.cc
+++ b/content/renderer/pepper/pepper_plugin_instance_impl.cc
@@ -110,6 +110,7 @@
 #include "third_party/WebKit/public/web/WebInputEvent.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
 #include "third_party/WebKit/public/web/WebPluginContainer.h"
+#include "third_party/WebKit/public/web/WebPluginScriptForbiddenScope.h"
 #include "third_party/WebKit/public/web/WebPrintParams.h"
 #include "third_party/WebKit/public/web/WebPrintPresetOptions.h"
 #include "third_party/WebKit/public/web/WebPrintScalingOption.h"
@@ -2371,6 +2372,8 @@ PP_Var PepperPluginInstanceImpl::ExecuteScript(PP_Instance instance,
                                                PP_Var* exception) {
   if (!container_)
     return PP_MakeUndefined();
+  if (is_deleted_ && blink::WebPluginScriptForbiddenScope::isForbidden())
+    return PP_MakeUndefined();
   RecordFlashJavaScriptUse();
 
   // Executing the script may remove the plugin from the DOM, so we need to keep