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

ui/views/accessibility/native_view_accessibility.h

 // Copyright (c) 2013 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.
 
 #ifndef UI_VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_H_
 #define UI_VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_H_
 
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "ui/accessibility/ax_action_data.h"
@@ skipping 31 matching lines @@
 
   // Call Destroy rather than deleting this, because the subclass may
   // use reference counting.
   virtual void Destroy();
 
   void NotifyAccessibilityEvent(ui::AXEvent event_type);
 
   // Focuses or unfocuses a View.
   bool SetFocused(bool focused);
 
-  // ui::AXPlatformNodeDelegate
+#if defined(OS_MACOSX)
+  // Checks if there are any keyboard focusable ancestors.
+  bool HasFocusableAncestor();

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

can this be moved to an anonymous namespace in the .cc only?

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

Good idea, thanks! I actually realised that just using
IsAccessibilityFocusable() isn't good enough - doing that would mean the
children of disabled controls (which would be accessibility focusable if they
were enabled) would not be ignored. So I had to make View::focusable_behavior()
public, not sure if that's an OK change?

+#endif
+
+  // ui::AXPlatformNodeDelegate:
   const ui::AXNodeData& GetData() override;
   int GetChildCount() override;
   gfx::NativeViewAccessible ChildAtIndex(int index) override;
   gfx::NativeWindow GetTopLevelWidget() override;
   gfx::NativeViewAccessible GetParent() override;
   gfx::Vector2d GetGlobalCoordinateOffset() override;
   gfx::NativeViewAccessible HitTestSync(int x, int y) override;
   gfx::NativeViewAccessible GetFocus() override;
   gfx::AcceleratedWidget GetTargetForNativeAccessibilityEvent() override;
   bool AccessibilityPerformAction(const ui::AXActionData& data) override;
   void DoDefaultAction() override;
 
-  // WidgetObserver
+  // WidgetObserver:
   void OnWidgetDestroying(Widget* widget) override;
 
   Widget* parent_widget() const { return parent_widget_; }
   void SetParentWidget(Widget* parent_widget);
 
  protected:
   NativeViewAccessibility(View* view);
   ~NativeViewAccessibility() override;
 
   // Weak. Owns this.
@@ skipping 12 matching lines @@
   ui::AXPlatformNode* ax_node_;
 
   ui::AXNodeData data_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeViewAccessibility);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_H_