Implement the inert attribute

third_party/WebKit/Source/core/dom/Node.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  *
@@ skipping 810 matching lines @@
 Node* Node::FocusDelegate() {
   return this;
 }
 
 bool Node::ShouldHaveFocusAppearance() const {
   DCHECK(IsFocused());
   return true;
 }
 
 bool Node::IsInert() const {
+  if (!CanParticipateInFlatTree())
+    return true;
+
+  DCHECK(!ChildNeedsDistributionRecalc());
+
   const HTMLDialogElement* dialog = GetDocument().ActiveModalDialog();
   if (dialog && this != GetDocument() &&
-      (!CanParticipateInFlatTree() ||
-       !FlatTreeTraversal::ContainsIncludingPseudoElement(*dialog, *this)))
+      !FlatTreeTraversal::ContainsIncludingPseudoElement(*dialog, *this)) {
     return true;
+  }
+
+  if (RuntimeEnabledFeatures::inertAttributeEnabled()) {
+    const Element* element = this->IsElementNode()
+                                 ? ToElement(this)
+                                 : FlatTreeTraversal::ParentElement(*this);
+    while (element) {
+      if (element->hasAttribute(HTMLNames::inertAttr))
+        return true;
+      element = FlatTreeTraversal::ParentElement(*element);
+    }
+  }
   return GetDocument().LocalOwner() && GetDocument().LocalOwner()->IsInert();

[dmazzoni, 2017/05/08 06:06:09]

I just realized this only walks local frames, so it won't work with
out-of-process iframes.

I think there's going to have to be a frame flag indicating whether
or not an entire frame / document is inert.

 }
 
 unsigned Node::NodeIndex() const {
   const Node* temp_node = previousSibling();
   unsigned count = 0;
   for (count = 0; temp_node; count++)
     temp_node = temp_node->previousSibling();
   return count;
 }
 
@@ skipping 1746 matching lines @@
   if (node) {
     std::stringstream stream;
     node->PrintNodePathTo(stream);
     LOG(INFO) << stream.str();
   } else {
     LOG(INFO) << "Cannot showNodePath for <null>";
   }
 }
 
 #endif