Make SecurityContext available in RemoteFrames.

Source/core/frame/LocalFrame.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Simon Hausmann <hausmann@kde.org>
  *                     2000 Stefan Schimanski <1Stein@gmx.de>
  *                     2001 George Staikos <staikos@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2005 Alexey Proskuryakov <ap@nypop.com>
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 263 matching lines @@
     InspectorInstrumentation::frameDetachedFromParent(this);
     Frame::detach();
 #if ENABLE(OILPAN)
     // Clear the FrameLoader right here rather than during
     // finalization. Too late to access various heap objects at that
     // stage.
     loader().clear();
 #endif
 }
 
+SecurityContext* LocalFrame::securityContext() const
+{
+    return document();
+}
+
 void LocalFrame::disconnectOwnerElement()
 {
     if (owner()) {
         if (Document* document = this->document())
             document->topDocument().clearAXObjectCache();
 #if ENABLE(OILPAN)
         // First give the plugin elements holding persisted,
         // renderer-less plugins the opportunity to dispose of them.
         for (const auto& pluginElement : m_pluginElements)
             pluginElement->disconnectContentFrame();
@@ skipping 494 matching lines @@
     // We detach the FrameView's custom scroll bars as early as
     // possible to prevent m_doc->detach() from messing with the view
     // such that its scroll bars won't be torn down.
     //
     // FIXME: We should revisit this.
     if (m_view)
         m_view->prepareForDetach();
 }
 
 } // namespace blink