Simplify inDetach() assert and make it stronger.

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 3407 matching lines @@
 }
 
 void Document::setAnnotatedRegions(const Vector<AnnotatedRegionValue>& regions)
 {
     m_annotatedRegions = regions;
     setAnnotatedRegionsDirty(false);
 }
 
 bool Document::setFocusedElement(PassRefPtrWillBeRawPtr<Element> prpNewFocusedElement, WebFocusType type)
 {
+    ASSERT(!m_lifecycle.inDetach());
+
     m_clearFocusedElementTimer.stop();
 
     RefPtrWillBeRawPtr<Element> newFocusedElement = prpNewFocusedElement;
 
     // Make sure newFocusedNode is actually in this document
     if (newFocusedElement && (newFocusedElement->document() != this))
         return true;
 
     if (NodeChildRemovalTracker::isBeingRemoved(newFocusedElement.get()))
         return true;
 
     if (m_focusedElement == newFocusedElement)
         return true;
 
     bool focusChangeBlocked = false;
     RefPtrWillBeRawPtr<Element> oldFocusedElement = m_focusedElement;
     m_focusedElement = nullptr;
 
     // Remove focus from the existing focus node (if any)
     if (oldFocusedElement) {
-        ASSERT(!oldFocusedElement->inDetach());
-
         if (oldFocusedElement->active())
             oldFocusedElement->setActive(false);
 
         oldFocusedElement->setFocus(false);
 
         // Dispatch the blur event and let the node do any other blur related activities (important for text fields)
         // If page lost focus, blur event will have already been dispatched
         if (page() && (page()->focusController().isFocused())) {
             oldFocusedElement->dispatchBlurEvent(newFocusedElement.get(), type);
 
@@ skipping 2278 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