Revert of service worker: Don't control a subframe of an insecure context

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 287 matching lines @@
 
 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)
         childFrames[i]->didChangeVisibilityState();
 }
 
-bool Frame::canHaveSecureChild() const
-{
-    for (const Frame* parent = this; parent; parent = parent->tree().parent()) {
-        if (!parent->securityContext()->getSecurityOrigin()->isPotentiallyTrustworthy())
-            return false;
-    }
-    return true;
-}
-
 Frame::Frame(FrameClient* client, FrameHost* host, FrameOwner* owner)
     : m_treeNode(this)
     , m_host(host)
     , m_owner(owner)
     , m_client(client)
     , m_isLoading(false)
 {
     InstanceCounters::incrementCounter(InstanceCounters::FrameCounter);
 
     ASSERT(page());
 
     if (m_owner)
         m_owner->setContentFrame(*this);
     else
         page()->setMainFrame(this);
 }
 
 } // namespace blink