Blur immediately if an attribute change made an element unfocasable.

third_party/WebKit/Source/core/html/HTMLAnchorElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights
  * reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 233 matching lines @@
   HTMLElement::defaultEventHandler(event);
 }
 
 void HTMLAnchorElement::setActive(bool down) {
   if (hasEditableStyle(*this))
     return;
 
   ContainerNode::setActive(down);
 }
 
+void HTMLAnchorElement::attributeChanged(const QualifiedName& name,
+                                         const AtomicString& oldValue,
+                                         const AtomicString& newValue,
+                                         AttributeModificationReason reason) {
+  HTMLElement::attributeChanged(name, oldValue, newValue, reason);
+  if (reason != AttributeModificationReason::kDirectly)
+    return;
+  if (name != hrefAttr && isLink())
+    return;
+  if (adjustedFocusedElementInTreeScope() != this)
+    return;
+  blur();
+}
+
 void HTMLAnchorElement::parseAttribute(const QualifiedName& name,
                                        const AtomicString& oldValue,
                                        const AtomicString& value) {
   if (name == hrefAttr) {
     bool wasLink = isLink();
     setIsLink(!value.isNull());
     if (wasLink || isLink()) {
       pseudoStateChanged(CSSSelector::PseudoLink);
       pseudoStateChanged(CSSSelector::PseudoVisited);
       pseudoStateChanged(CSSSelector::PseudoAnyLink);
     }
-    if (wasLink && !isLink() && adjustedFocusedElementInTreeScope() == this) {
-      // We might want to call blur(), but it's dangerous to dispatch
-      // events here.
-      document().setNeedsFocusedElementCheck();
-    }
     if (isLink()) {
       String parsedURL = stripLeadingAndTrailingHTMLSpaces(value);
       if (document().isDNSPrefetchEnabled()) {
         if (protocolIs(parsedURL, "http") || protocolIs(parsedURL, "https") ||
             parsedURL.startsWith("//"))
           prefetchDNS(document().completeURL(parsedURL).host());
       }
     }
     invalidateCachedVisitedLinkHash();
     logUpdateAttributeIfIsolatedWorldAndInDocument("a", hrefAttr, oldValue,
@@ skipping 196 matching lines @@
 }
 
 HTMLAnchorElement::NavigationHintSender*
 HTMLAnchorElement::ensureNavigationHintSender() {
   if (!m_navigationHintSender)
     m_navigationHintSender = NavigationHintSender::create(this);
   return m_navigationHintSender;
 }
 
 }  // namespace blink