a11y: Exclude children of nested keyboard accessible controls from a11y tree.

ui/views/accessibility/native_view_accessibility.cc

Index: ui/views/accessibility/native_view_accessibility.cc
diff --git a/ui/views/accessibility/native_view_accessibility.cc b/ui/views/accessibility/native_view_accessibility.cc
index a984c3c6c08c901fbe65b13d87166e5c075d3a78..3af5f52fef15530d6404de36c842d5b6b9dc552f 100644
--- a/ui/views/accessibility/native_view_accessibility.cc
+++ b/ui/views/accessibility/native_view_accessibility.cc
@@ -96,7 +96,16 @@ const ui::AXNodeData& NativeViewAccessibility::GetData() {
 }
 
 int NativeViewAccessibility::GetChildCount() {
-  int child_count = view_->child_count();
+  int child_count = 0;
+  for (int i = 0; i < view_->child_count(); ++i) {
+    View* child = view_->child_at(i);
+    if (child->GetNativeViewAccessibility()->IsIgnored()) {
+      // If not visible to accessibility clients, then use the children instead.
+      child_count += child->GetNativeViewAccessibility()->GetChildCount();
+    } else {
+      ++child_count;
+    }
+  }
 
   std::vector<Widget*> child_widgets;
   PopulateChildWidgetVector(&child_widgets);
@@ -106,14 +115,32 @@ int NativeViewAccessibility::GetChildCount() {
 }
 
 gfx::NativeViewAccessible NativeViewAccessibility::ChildAtIndex(int index) {
-  // If this is a root view, our widget might have child widgets. Include
+  if (IsLeafElement())
+    return nullptr;
+
+  // Include the child widgets that may be present if this is a root view.
   std::vector<Widget*> child_widgets;
   PopulateChildWidgetVector(&child_widgets);
   int child_widget_count = static_cast<int>(child_widgets.size());
 
-  if (index < view_->child_count()) {
-    return view_->child_at(index)->GetNativeViewAccessible();
-  } else if (index < view_->child_count() + child_widget_count) {
+  int ax_child_count = GetChildCount();
+  if (index < ax_child_count) {
+    int curr_child_count = 0;
+    for (int i = 0; i < view_->child_count(); ++i) {
+      View* child = view_->child_at(i);
+      bool ignored = child->GetNativeViewAccessibility()->IsIgnored();
+      int pending_children =
+          ignored ? child->GetNativeViewAccessibility()->GetChildCount() : 1;
+      if (index < curr_child_count + pending_children) {
+        if (ignored) {
+          return child->GetNativeViewAccessibility()->ChildAtIndex(
+              index - curr_child_count);
+        }
+        return child->GetNativeViewAccessible();
+      }
+      curr_child_count += pending_children;
+    }
+  } else if (index < ax_child_count + child_widget_count) {
     Widget* child_widget = child_widgets[index - view_->child_count()];
     return child_widget->GetRootView()->GetNativeViewAccessible();
   }
@@ -128,8 +155,13 @@ gfx::NativeWindow NativeViewAccessibility::GetTopLevelWidget() {
 }
 
 gfx::NativeViewAccessible NativeViewAccessibility::GetParent() {
-  if (view_->parent())
-    return view_->parent()->GetNativeViewAccessible();
+  View* parent_view = view_->parent();
+  if (parent_view) {
+    if (parent_view->GetNativeViewAccessibility()->IsIgnored())
+      return parent_view->GetNativeViewAccessibility()->GetParent();
+    else
+      return parent_view->GetNativeViewAccessible();
+  }
 
   // TODO: move this to NativeViewAccessibilityMac.
 #if defined(OS_MACOSX)
@@ -162,14 +194,20 @@ gfx::NativeViewAccessible NativeViewAccessibility::HitTestSync(int x, int y) {
       return child_root_view->GetNativeViewAccessible();
   }
 
+  if (IsLeafElement()) {
+    if (IsIgnored())
+      return GetParent();
+    return GetNativeObject();
+  }
+
   gfx::Point point(x, y);
   View::ConvertPointFromScreen(view_, &point);
   if (!view_->HitTestPoint(point))
     return nullptr;
 
-  // Check if the point is within any of the immediate children of this
-  // view. We don't have to search further because AXPlatformNode will
-  // do a recursive hit test if we return anything other than |this| or NULL.
+  // Check if the point is within any of the immediate children of this view. We
+  // don't have to search further because AXPlatformNodeWin will do a recursive
+  // hit test if we return anything other than |GetNativeObject()| or nullptr.
   for (int i = view_->child_count() - 1; i >= 0; --i) {
     View* child_view = view_->child_at(i);
     if (!child_view->visible())
@@ -245,6 +283,18 @@ void NativeViewAccessibility::SetParentWidget(Widget* parent_widget) {
   parent_widget_->AddObserver(this);
 }
 
+bool NativeViewAccessibility::IsLeafElement() {
+  if (GetChildCount() != 0)
+    return false;
+  return true;
+}
+
+bool NativeViewAccessibility::IsIgnored() {
+  if (view_->focus_behavior() == ClientView::FocusBehavior::NEVER)
+    return true;
+  return false;
+}
+
 void NativeViewAccessibility::PopulateChildWidgetVector(
     std::vector<Widget*>* result_child_widgets) {
   // Only attach child widgets to the root view.