content-visibility: Fix inspector DCHECK when inspecting cv iframe contents

This patch changes the content-visibility check in the inspector code
to make sure that we consider ancestor frames as locked as well.

R=chrishtr@chromium.org

Bug: 1128790
Change-Id: Ie8a4dfebb694bbe50e8c5179ccd9e8cdcc57c35b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2422244Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Commit-Queue: vmpstr <vmpstr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#809180}

third_party/blink/renderer/core/display_lock/display_lock_utilities.cc

@@ -24,7 +24,7 @@ namespace {
 
 // Returns the frame owner node for the frame that contains the given child, if
 // one exists. Returns nullptr otherwise.
-const Node* GetFrameOwnerNode(const Node* child) {
+Node* GetFrameOwnerNode(const Node* child) {
   if (!child || !child->GetDocument().GetFrame() ||
       !child->GetDocument().GetFrame()->OwnerLayoutObject()) {
     return nullptr;
@@ -320,40 +320,53 @@ Element* DisplayLockUtilities::NearestLockedExclusiveAncestor(
 Element* DisplayLockUtilities::HighestLockedInclusiveAncestor(
     const Node& node) {
   if (!RuntimeEnabledFeatures::CSSContentVisibilityEnabled() ||
-      node.GetDocument()
-              .GetDisplayLockDocumentState()
-              .LockedDisplayLockCount() == 0 ||
       !node.CanParticipateInFlatTree()) {
     return nullptr;
   }
-  const_cast<Node*>(&node)->UpdateDistributionForFlatTreeTraversal();
-  Element* locked_ancestor = nullptr;
-  for (Node& ancestor : FlatTreeTraversal::InclusiveAncestorsOf(node)) {
-    auto* ancestor_node = DynamicTo<Element>(ancestor);
-    if (!ancestor_node)
-      continue;
-    if (auto* context = ancestor_node->GetDisplayLockContext()) {
-      if (context->IsLocked())
-        locked_ancestor = ancestor_node;
-    }
+  auto* node_ptr = const_cast<Node*>(&node);
+  node_ptr->UpdateDistributionForFlatTreeTraversal();
+  // If the exclusive result exists, then that's higher than this node, so
+  // return it.
+  if (auto* result = HighestLockedExclusiveAncestor(node))
+    return result;
+
+  // Otherwise, we know the node is not in a locked subtree, so the only
+  // other possibility is that the node itself is locked.
+  auto* element = DynamicTo<Element>(node_ptr);
+  if (element && element->GetDisplayLockContext() &&
+      element->GetDisplayLockContext()->IsLocked()) {
+    return element;
   }
-  return locked_ancestor;
+  return nullptr;
 }
 
 Element* DisplayLockUtilities::HighestLockedExclusiveAncestor(
     const Node& node) {
   if (!RuntimeEnabledFeatures::CSSContentVisibilityEnabled() ||
-      node.GetDocument()
-              .GetDisplayLockDocumentState()
-              .LockedDisplayLockCount() == 0 ||
       !node.CanParticipateInFlatTree()) {
     return nullptr;
   }
   const_cast<Node*>(&node)->UpdateDistributionForFlatTreeTraversal();
 
-  if (Node* parent = FlatTreeTraversal::Parent(node))
-    return HighestLockedInclusiveAncestor(*parent);
-  return nullptr;
+  Node* parent = FlatTreeTraversal::Parent(node);
+  Element* locked_ancestor = nullptr;
+  while (parent) {
+    auto* locked_candidate = NearestLockedInclusiveAncestor(*parent);
+    auto* last_node = parent;
+    if (locked_candidate) {
+      locked_ancestor = locked_candidate;
+      parent = FlatTreeTraversal::Parent(*parent);
+    } else {
+      parent = nullptr;
+    }
+
+    if (!parent) {
+      parent = GetFrameOwnerNode(last_node);
+      if (parent)
+        parent->UpdateDistributionForFlatTreeTraversal();
+    }
+  }
+  return locked_ancestor;
 }
 
 Element* DisplayLockUtilities::NearestLockedInclusiveAncestor(

third_party/blink/renderer/core/display_lock/display_lock_utilities.h

@@ -118,11 +118,10 @@ class CORE_EXPORT DisplayLockUtilities {
   // locked.
   static Element* NearestLockedExclusiveAncestor(const Node& node);
 
-  // Returns the highest inclusive ancestor of |node| that is display locked.
-  static Element* HighestLockedInclusiveAncestor(const Node& node);
-
   // Returns the highest exclusive ancestor of |node| that is display locked.
+  // Note that this function crosses local frames.
   static Element* HighestLockedExclusiveAncestor(const Node& node);
+  static Element* HighestLockedInclusiveAncestor(const Node& node);
 
   // LayoutObject versions of the NearestLocked* ancestor functions.
   static Element* NearestLockedInclusiveAncestor(const LayoutObject& object);

third_party/blink/web_tests/http/tests/devtools/elements/highlight/highlight-display-locked-in-frame-expected.txt

+Tests highlights for display locking in a frame.
+
+container{
+  "paths": [
+    {
+      "path": [
+        "M",
+        10,
+        10,
+        "L",
+        20,
+        10,
+        "L",
+        20,
+        20,
+        "L",
+        10,
+        20,
+        "Z"
+      ],
+      "fillColor": "rgba(255, 0, 0, 0)",
+      "outlineColor": "rgba(128, 0, 0, 0)",
+      "name": "content"
+    },
+    {
+      "path": [
+        "M",
+        10,
+        10,
+        "L",
+        20,
+        10,
+        "L",
+        20,
+        20,
+        "L",
+        10,
+        20,
+        "Z"
+      ],
+      "fillColor": "rgba(0, 255, 0, 0)",
+      "name": "padding"
+    },
+    {
+      "path": [
+        "M",
+        8,
+        8,
+        "L",
+        22,
+        8,
+        "L",
+        22,
+        22,
+        "L",
+        8,
+        22,
+        "Z"
+      ],
+      "fillColor": "rgba(0, 0, 255, 0)",
+      "name": "border"
+    },
+    {
+      "path": [
+        "M",
+        8,
+        8,
+        "L",
+        22,
+        8,
+        "L",
+        22,
+        22,
+        "L",
+        8,
+        22,
+        "Z"
+      ],
+      "fillColor": "rgba(255, 255, 255, 0)",
+      "name": "margin"
+    }
+  ],
+  "showRulers": true,
+  "showExtensionLines": true,
+  "showAccessibilityInfo": true,
+  "colorFormat": "hex",
+  "elementInfo": {
+    "tagName": "iframe",
+    "idValue": "container",
+    "nodeWidth": "14",
+    "nodeHeight": "14",
+    "isKeyboardFocusable": false,
+    "accessibleName": "",
+    "accessibleRole": "",
+    "layoutObjectName": "LayoutIFrame",
+    "showAccessibilityInfo": true
+  }
+}
+child{
+  "paths": [
+    {
+      "path": [
+        "M",
+        10,
+        10,
+        "L",
+        20,
+        10,
+        "L",
+        20,
+        20,
+        "L",
+        10,
+        20,
+        "Z"
+      ],
+      "fillColor": "rgba(255, 0, 0, 0)",
+      "outlineColor": "rgba(128, 0, 0, 0)",
+      "name": "content"
+    },
+    {
+      "path": [
+        "M",
+        10,
+        10,
+        "L",
+        20,
+        10,
+        "L",
+        20,
+        20,
+        "L",
+        10,
+        20,
+        "Z"
+      ],
+      "fillColor": "rgba(0, 255, 0, 0)",
+      "name": "padding"
+    },
+    {
+      "path": [
+        "M",
+        8,
+        8,
+        "L",
+        22,
+        8,
+        "L",
+        22,
+        22,
+        "L",
+        8,
+        22,
+        "Z"
+      ],
+      "fillColor": "rgba(0, 0, 255, 0)",
+      "name": "border"
+    },
+    {
+      "path": [
+        "M",
+        8,
+        8,
+        "L",
+        22,
+        8,
+        "L",
+        22,
+        22,
+        "L",
+        8,
+        22,
+        "Z"
+      ],
+      "fillColor": "rgba(255, 255, 255, 0)",
+      "name": "margin"
+    }
+  ],
+  "showRulers": true,
+  "showExtensionLines": true,
+  "showAccessibilityInfo": true,
+  "colorFormat": "hex",
+  "elementInfo": {
+    "tagName": "iframe",
+    "idValue": "container",
+    "nodeWidth": "14",
+    "nodeHeight": "14",
+    "isKeyboardFocusable": false,
+    "accessibleName": "",
+    "accessibleRole": "",
+    "layoutObjectName": "LayoutIFrame",
+    "isLockedAncestor": "true",
+    "showAccessibilityInfo": true
+  }
+}
+

third_party/blink/web_tests/http/tests/devtools/elements/highlight/highlight-display-locked-in-frame.js

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+(async function() {
+  TestRunner.addResult(`Tests highlights for display locking in a frame.\n`);
+  await TestRunner.loadModule('elements_test_runner');
+  await TestRunner.loadModule('console_test_runner');
+  await TestRunner.showPanel('elements');
+  await TestRunner.loadHTML(`
+      <iframe id="container" style="content-visibility: hidden; contain-intrinsic-size: 10px;"
+        srcdoc='<div id="child" style="width: 50px; height: 50px; background: blue">Text</div>'
+      </iframe>
+    `);
+
+  function dumpChild() {
+    ElementsTestRunner.dumpInspectorHighlightJSON('child', TestRunner.completeTest.bind(TestRunner));
+  }
+
+  function dumpContainerAndChild() {
+    ElementsTestRunner.dumpInspectorHighlightJSON('container', dumpChild);
+  }
+
+  dumpContainerAndChild();
+})();