[selectors4] Use common ancestor strategy for :focus-within

third_party/WebKit/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.
@@ skipping 4036 matching lines @@
   if (NodeChildRemovalTracker::IsBeingRemoved(new_focused_element))
     return true;
 
   if (focused_element_ == new_focused_element)
     return true;
 
   bool focus_change_blocked = false;
   Element* old_focused_element = focused_element_;
   focused_element_ = nullptr;
 
+  UpdateDistribution();
+  Node* ancestor = (old_focused_element && old_focused_element->isConnected() &&
+                    new_focused_element)
+                       ? FlatTreeTraversal::CommonAncestor(*old_focused_element,
+                                                           *new_focused_element)
+                       : nullptr;
+
   // Remove focus from the existing focus node (if any)
   if (old_focused_element) {
     old_focused_element->SetFocused(false, params.type);
+    old_focused_element->SetHasFocusWithinUpToAncestor(false, ancestor);
 
     // 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 (GetPage() && (GetPage()->GetFocusController().IsFocused())) {
       old_focused_element->DispatchBlurEvent(new_focused_element, params.type,
                                              params.source_capabilities);
       if (focused_element_) {
         // handler shifted focus
         focus_change_blocked = true;
@@ skipping 27 matching lines @@
         !AcceptsEditingFocus(*new_focused_element)) {
       // delegate blocks focus change
       focus_change_blocked = true;
       goto SetFocusedElementDone;
     }
     // Set focus on the new node
     focused_element_ = new_focused_element;
     SetSequentialFocusNavigationStartingPoint(focused_element_.Get());
 
     focused_element_->SetFocused(true, params.type);
+    focused_element_->SetHasFocusWithinUpToAncestor(true, ancestor);
+
     // Element::setFocused for frames can dispatch events.
     if (focused_element_ != new_focused_element) {
       focus_change_blocked = true;
       goto SetFocusedElementDone;
     }
     CancelFocusAppearanceUpdate();
     focused_element_->UpdateFocusAppearance(params.selection_behavior);
 
     // Dispatch the focus event and let the node do any other focus related
     // activities (important for text fields)
@@ skipping 2535 matching lines @@
 }
 
 void showLiveDocumentInstances() {
   WeakDocumentSet& set = liveDocumentSet();
   fprintf(stderr, "There are %u documents currently alive:\n", set.size());
   for (blink::Document* document : set)
     fprintf(stderr, "- Document %p URL: %s\n", document,
             document->Url().GetString().Utf8().Data());
 }
 #endif