Expose some tables with CSS display rules as data tables

For <table style="display:foo">, do not immediately assume it is
for layout, just because there is no table layout interface.

A follow-up CL will transform IsDataTable() to rely much more on
DOM interfaces, rather than layout interfaces.

Bug: 1011067

Change-Id: Iebb6224d311f09b1b3bf6e6aa08efbe7393b42d2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2079267
Auto-Submit: Aaron Leventhal <aleventhal@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: Aaron Leventhal <aleventhal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#746392}

content/browser/accessibility/dump_accessibility_tree_browsertest.cc

@@ -288,6 +288,11 @@ IN_PROC_BROWSER_TEST_P(DumpAccessibilityTreeTest,
   RunCSSTest(FILE_PATH_LITERAL("table-display-other.html"));
 }
 
+IN_PROC_BROWSER_TEST_P(DumpAccessibilityTreeTest,
+                       AccessibilityCSSDataTableDisplayOther) {
+  RunCSSTest(FILE_PATH_LITERAL("table-data-display-other.html"));
+}
+
 IN_PROC_BROWSER_TEST_P(DumpAccessibilityTreeTest, AccessibilityCSSTransform) {
   RunCSSTest(FILE_PATH_LITERAL("transform.html"));
 }

content/test/data/accessibility/css/table-data-display-other-expected-blink.txt

+rootWebArea
+++genericContainer ignored
+++++table tableRowCount=2 tableColumnCount=3
+++++++rowGroup ignored
+++++++++row tableRowIndex=0
+++++++++++columnHeader name='1' tableCellColumnIndex=0 tableCellRowIndex=0
+++++++++++++staticText name='1'
+++++++++++++++inlineTextBox name='1'
+++++++++++columnHeader name='2' tableCellColumnIndex=1 tableCellRowIndex=0
+++++++++++++staticText name='2'
+++++++++++++++inlineTextBox name='2'
+++++++++++columnHeader name='3' tableCellColumnIndex=2 tableCellRowIndex=0
+++++++++++++staticText name='3'
+++++++++++++++inlineTextBox name='3'
+++++++rowGroup ignored
+++++++++row tableRowIndex=1
+++++++++++cell name='a' tableCellColumnIndex=0 tableCellRowIndex=1
+++++++++++++staticText name='a'
+++++++++++++++inlineTextBox name='a'
+++++++++++cell name='b' tableCellColumnIndex=1 tableCellRowIndex=1
+++++++++++++staticText name='b'
+++++++++++++++inlineTextBox name='b'
+++++++++++cell name='c' tableCellColumnIndex=2 tableCellRowIndex=1
+++++++++++++staticText name='c'
+++++++++++++++inlineTextBox name='c'

content/test/data/accessibility/css/table-data-display-other.html

+<!--
+@BLINK-ALLOW:tableColumnCount*
+@BLINK-ALLOW:tableRowCount*
+@BLINK-ALLOW:table*Index*
+-->
+<!-- Ensure that a table with display styles and other semantic table markup
+  is still exposed as a data table.. -->
+<style>
+table, thead, tbody, tr, td { display: flex; }
+</style>
+<table>
+  <thead>
+    <tr>
+      <th>1</th>
+      <th>2</th>
+      <th>3</th>
+    </tr>
+  </thead>
+  <tbody>
+    <tr>
+      <td>a</td>
+      <td>b</td>
+      <td>c</td>
+    </tr>
+  </tbody>
+</table>

third_party/blink/renderer/modules/accessibility/ax_layout_object.cc

@@ -2436,27 +2436,17 @@ bool AXLayoutObject::IsDataTable() const {
   if (HasAOMPropertyOrARIAAttribute(AOMStringProperty::kRole, role))
     return true;
 
-  if (!layout_object_->IsTable())
-    return false;
-
   // When a section of the document is contentEditable, all tables should be
   // treated as data tables, otherwise users may not be able to work with rich
   // text editors that allow creating and editing tables.
   if (GetNode() && HasEditableStyle(*GetNode()))
     return true;
 
-  // If there's no node, it's definitely a layout table. This happens
-  // when table CSS styles are used without a complete table DOM structure.
-  LayoutNGTableInterface* table =
-      ToInterface<LayoutNGTableInterface>(layout_object_);
-  table->RecalcSectionsIfNeeded();
-  Node* table_node = layout_object_->GetNode();
-
   // This employs a heuristic to determine if this table should appear.
   // Only "data" tables should be exposed as tables.
   // Unfortunately, there is no good way to determine the difference
   // between a "layout" table and a "data" table.
-  auto* table_element = DynamicTo<HTMLTableElement>(table_node);
+  auto* table_element = DynamicTo<HTMLTableElement>(GetNode());
   if (!table_element)
     return false;
 
@@ -2474,6 +2464,23 @@ bool AXLayoutObject::IsDataTable() const {
   if (Traversal<HTMLTableColElement>::FirstChild(*table_element))
     return true;
 
+  // Everything from here forward uses cell style info, but only if a CSS table.
+  // If this code is reached for a <table> with another display type, consider
+  // this to be a layout table.
+  // TODO(accessibility) consider rewriting the following cell inspection code
+  // using purely DOM methods, such as table->rows()->Item(index)->cells().
+  if (!layout_object_->IsTable())
+    return false;
+
+  // If there's no node, it's definitely a layout table. This happens
+  // when table CSS styles are used without a complete table DOM structure.
+  LayoutNGTableInterface* table =
+      ToInterface<LayoutNGTableInterface>(layout_object_);
+  table->RecalcSectionsIfNeeded();
+  Node* table_node = layout_object_->GetNode();
+  if (!table_node)
+    return false;
+
   // go through the cell's and check for tell-tale signs of "data" table status
   // cells have borders, or use attributes like headers, abbr, scope or axis
   table->RecalcSectionsIfNeeded();