Log to UMA when x-origin frames (1) are created and (2) become visible

third_party/WebKit/Source/core/frame/Frame.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 @@
 Settings* Frame::settings() const
 {
     if (m_host)
         return &m_host->settings();
     return nullptr;
 }
 
 bool Frame::isCrossOrigin() const
 {
     // Check to see if the frame can script into the top level document.
-    const SecurityOrigin* securityOrigin = securityContext()->getSecurityOrigin();
+    SecurityContext* context = securityContext();
+    DCHECK(context);
+    const SecurityOrigin* securityOrigin = context->getSecurityOrigin();
     Frame* top = tree().top();
     return top && !securityOrigin->canAccess(top->securityContext()->getSecurityOrigin());
 }
 
 void Frame::didChangeVisibilityState()
 {
     HeapVector<Member<Frame>> childFrames;
     for (Frame* child = tree().firstChild(); child; child = child->tree().nextSibling())
         childFrames.append(child);
     for (size_t i = 0; i < childFrames.size(); ++i)
@@ skipping 11 matching lines @@
 
     ASSERT(page());
 
     if (m_owner)
         m_owner->setContentFrame(*this);
     else
         page()->setMainFrame(this);
 }
 
 } // namespace blink