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

ui/views/accessibility/native_view_accessibility.h

Index: ui/views/accessibility/native_view_accessibility.h
diff --git a/ui/views/accessibility/native_view_accessibility.h b/ui/views/accessibility/native_view_accessibility.h
index 95fcc3de365335cae6225445619c55bb91f72687..a94813b22d494eaf686daa5fe8444e6490576a23 100644
--- a/ui/views/accessibility/native_view_accessibility.h
+++ b/ui/views/accessibility/native_view_accessibility.h
@@ -45,7 +45,7 @@ class VIEWS_EXPORT NativeViewAccessibility
 
   void NotifyAccessibilityEvent(ui::AXEvent event_type);
 
-  // ui::AXPlatformNodeDelegate
+  // ui::AXPlatformNodeDelegate:
   const ui::AXNodeData& GetData() override;
   int GetChildCount() override;
   gfx::NativeViewAccessible ChildAtIndex(int index) override;
@@ -58,13 +58,17 @@ class VIEWS_EXPORT NativeViewAccessibility
   void DoDefaultAction() override;
   bool SetStringValue(const base::string16& new_value) override;
   bool CanSetStringValue() override;
+  bool IsIgnored() override;
 
-  // WidgetObserver
+  // WidgetObserver:
   void OnWidgetDestroying(Widget* widget) override;
 
   Widget* parent_widget() const { return parent_widget_; }
   void SetParentWidget(Widget* parent_widget);
 
+  // Whether the accessibility element has any unignored children.
+  bool IsLeafElement();
+
  protected:
   NativeViewAccessibility(View* view);
   ~NativeViewAccessibility() override;