Mixed Content: Implement strict mode.

Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 4759 matching lines @@
         m_cookieURL = KURL(ParsedURLString, emptyString());
         setSecurityOrigin(SecurityOrigin::createUnique());
         initContentSecurityPolicy();
         return;
     }
 
     // In the common case, create the security context from the currently
     // loading URL with a fresh content security policy.
     m_cookieURL = m_url;
     enforceSandboxFlags(initializer.sandboxFlags());
+    if (initializer.shouldEnforceStrictMixedContentChecking())
+        enforceStrictMixedContentChecking();
     setSecurityOrigin(isSandboxed(SandboxOrigin) ? SecurityOrigin::createUnique() : SecurityOrigin::create(m_url));
 
     if (importsController()) {
         // If this document is an HTML import, grab a reference to it's master document's Content
         // Security Policy. We don't call 'initContentSecurityPolicy' in this case, as we can't
         // rebind the master document's policy object: its ExecutionContext needs to remain tied
         // to the master document.
         setContentSecurityPolicy(importsController()->master()->contentSecurityPolicy());
     } else {
         initContentSecurityPolicy();
@@ skipping 1046 matching lines @@
 #ifndef NDEBUG
 using namespace blink;
 void showLiveDocumentInstances()
 {
     WeakDocumentSet& set = liveDocumentSet();
     fprintf(stderr, "There are %u documents currently alive:\n", set.size());
     for (Document* document : set)
         fprintf(stderr, "- Document %p URL: %s\n", document, document->url().string().utf8().data());
 }
 #endif