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 7c960348478b020d7b0bfeed5adf0f50f45e5d70..fa7ac3343d9070480fe0e9fd3be8f88d901d78df 100644
--- a/ui/views/accessibility/native_view_accessibility.cc
+++ b/ui/views/accessibility/native_view_accessibility.cc
@@ -58,6 +58,17 @@ bool NativeViewAccessibility::SetFocused(bool focused) {
   return true;
 }
 
+#if defined(OS_MACOSX)
+bool NativeViewAccessibility::HasFocusableAncestor() {
+  View* parent = view_;
+  while ((parent = parent->parent())) {
+    if (parent->IsAccessibilityFocusable())
+      return true;
+  }
+  return false;
+}
+#endif
+
 // ui::AXPlatformNodeDelegate
 
 const ui::AXNodeData& NativeViewAccessibility::GetData() {
@@ -80,13 +91,20 @@ const ui::AXNodeData& NativeViewAccessibility::GetData() {
                            base::UTF16ToUTF8(description));
 
   if (view_->IsAccessibilityFocusable())
-    data_.state |= (1 << ui::AX_STATE_FOCUSABLE);
+    data_.AddStateFlag(ui::AX_STATE_FOCUSABLE);
 
   if (!view_->enabled())
-    data_.state |= (1 << ui::AX_STATE_DISABLED);
+    data_.AddStateFlag(ui::AX_STATE_DISABLED);
 
   if (!view_->visible())
-    data_.state |= (1 << ui::AX_STATE_INVISIBLE);
+    data_.AddStateFlag(ui::AX_STATE_INVISIBLE);
+
+#if defined(OS_MACOSX)
+  // Make sure this element is ignored if there's a focusable parent. All
+  // keyboard focusable elements should be leaf nodes in the accessibility tree.
+  if (HasFocusableAncestor())

[tapted, 2016/11/25 04:36:27]

should we do this only if the view itself is not accessibility focusable? I
think it's allowed to traverse things inside something that is focusable.

An example might be something like the omnibox which gets icons within it.

[Patti Lor, 2016/11/28 06:40:23]

That sounds reasonable - I don't think it fixes the Omnibox problems (see
below), but have added this in anyway.

The star was always working with VO, but the LocationIconView (which is the lock
icon/info icon and stuff to the left of the Omnibox) never did. A clean build
makes it show up to VO separately as image + label, then with the changes in
this CL, it's completely ignored. I've filed a bug to fix this in a follow up CL
here: https://bugs.chromium.org/p/chromium/issues/detail?id=668930, and I think
I know how to do it.

(To be clear, the change you've suggested above doesn't fix it, it's still
ignored.)

+    data_.role = ui::AX_ROLE_UNKNOWN;
+#endif
 
   return data_;
 }
@@ -140,7 +158,7 @@ gfx::NativeViewAccessible NativeViewAccessibility::GetParent() {
 }
 
 gfx::Vector2d NativeViewAccessibility::GetGlobalCoordinateOffset() {
-  return gfx::Vector2d(0, 0);  // location is already in screen coordinates.
+  return gfx::Vector2d(0, 0);  // Location is already in screen coordinates.
 }
 
 gfx::NativeViewAccessible NativeViewAccessibility::HitTestSync(int x, int y) {
@@ -163,9 +181,9 @@ gfx::NativeViewAccessible NativeViewAccessibility::HitTestSync(int x, int y) {
   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())