Revert of Revert of Reland factor out window proxy management portions of ScriptController.

Source/web/WebLocalFrameImpl.cpp

Index: Source/web/WebLocalFrameImpl.cpp
diff --git a/Source/web/WebLocalFrameImpl.cpp b/Source/web/WebLocalFrameImpl.cpp
index 054d85d2d4248bce2b4b8ffbfebecd3d0af9b719..b2810a241a4528b615bdadbeedf4b89227d506fd 100644
--- a/Source/web/WebLocalFrameImpl.cpp
+++ b/Source/web/WebLocalFrameImpl.cpp
@@ -153,6 +153,7 @@
 #include "modules/push_messaging/PushController.h"
 #include "modules/screen_orientation/ScreenOrientationController.h"
 #include "modules/speech/SpeechRecognitionController.h"
+#include "platform/ScriptForbiddenScope.h"
 #include "platform/TraceEvent.h"
 #include "platform/UserGestureIndicator.h"
 #include "platform/clipboard/ClipboardUtilities.h"
@@ -707,7 +708,7 @@ void WebLocalFrameImpl::dispatchUnloadEvent()
 
 NPObject* WebLocalFrameImpl::windowObject() const
 {
-    if (!frame())
+    if (!frame() || ScriptForbiddenScope::isScriptForbidden())
         return 0;
     return frame()->script().windowScriptNPObject();
 }