Navigation transitions: Hide transition elements by setting CSS opacity rather than display.

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 5623 matching lines @@
 
 void Document::hideTransitionElements(const AtomicString& cssSelector)
 {
     TrackExceptionState exceptionState;
     RefPtrWillBeRawPtr<StaticElementList> elementList = querySelectorAll(cssSelector, exceptionState);
     if (elementList && !exceptionState.hadException()) {
         unsigned nodeListLength = elementList->length();
 
         for (unsigned nodeIndex = 0; nodeIndex < nodeListLength; ++nodeIndex) {
             Element* element = elementList->item(nodeIndex);
-            element->setInlineStyleProperty(CSSPropertyDisplay, CSSValueNone);
+            element->setInlineStyleProperty(CSSPropertyOpacity, 0.0, CSSPrimitiveValue::CSS_NUMBER);
         }
     }
 }
 
 bool Document::hasFocus() const
 {
     Page* page = this->page();
     if (!page)
         return false;
     if (!page->focusController().isActive() || !page->focusController().isFocused())
@@ skipping 135 matching lines @@
 using namespace blink;
 void showLiveDocumentInstances()
 {
     WeakDocumentSet& set = liveDocumentSet();
     fprintf(stderr, "There are %u documents currently alive:\n", set.size());
     for (WeakDocumentSet::const_iterator it = set.begin(); it != set.end(); ++it) {
         fprintf(stderr, "- Document %p URL: %s\n", *it, (*it)->url().string().utf8().data());
     }
 }
 #endif