A focused element should lose focus when it becomes unfocusable.

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index e3ff783900ca656fd499106a88c7daf2f48be5c4..1eeb7cb2c6fb94b4aee23bdb56b4cb09066f8f89 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -384,6 +384,27 @@ static void printNavigationErrorMessage(Frame* frame, const KURL& activeURL, con
 
 uint64_t Document::s_globalTreeVersion = 0;
 
+// This class should be passed only to Document::postTask.
+class FocusedNodeChecker: public ScriptExecutionContext::Task {

[esprehn, 2013/05/20 22:03:44]

Missing a space before : and this should be FINAL

[tkent, 2013/05/20 22:29:45]

Done.

+public:
+    static PassOwnPtr<FocusedNodeChecker> create()
+    {
+        return adoptPtr(new FocusedNodeChecker());
+    }
+    virtual ~FocusedNodeChecker() { }
+
+private:
+    FocusedNodeChecker() { }

[esprehn, 2013/05/20 22:03:44]

It be nicer if this was called CheckFocusedNodeTask or something of that nature.

[tkent, 2013/05/20 22:29:45]

Done.

+    virtual void performTask(ScriptExecutionContext* context) OVERRIDE
+    {
+        ASSERT(context->isDocument());
+        Document* document = toDocument(context);
+        document->didRunFocusedNodeCheker();
+        if (document->focusedNode() && !document->focusedNode()->isFocusable())
+            document->setFocusedNode(0);
+    }
+};
+
 Document::Document(Frame* frame, const KURL& url, bool isXHTML, bool isHTML)
     : ContainerNode(0, CreateDocument)
     , TreeScope(this)
@@ -393,6 +414,7 @@ Document::Document(Frame* frame, const KURL& url, bool isXHTML, bool isHTML)
     , m_contextFeatures(ContextFeatures::defaultSwitch())
     , m_compatibilityMode(NoQuirksMode)
     , m_compatibilityModeLocked(false)
+    , m_didPostFocusedNodeChecker(false)
     , m_domTreeVersion(++s_globalTreeVersion)
     , m_mutationObserverTypes(0)
     , m_styleSheetCollection(DocumentStyleSheetCollection::create(this))
@@ -1808,6 +1830,11 @@ void Document::updateLayout()
     // Only do a layout if changes have occurred that make it necessary.      
     if (frameView && renderer() && (frameView->layoutPending() || renderer()->needsLayout()))
         frameView->layout();
+
+    if (m_focusedNode && !m_didPostFocusedNodeChecker) {
+        postTask(FocusedNodeChecker::create());
+        m_didPostFocusedNodeChecker = true;
+    }
 }
 
 // FIXME: This is a bad idea and needs to be removed eventually.