Views a11y: Implement AXPlatformNode::FromNativeViewAccessible on all platforms.

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 22 matching lines @@
 
 namespace views {
 
 class View;
 class Widget;
 
 class VIEWS_EXPORT NativeViewAccessibility
     : public ui::AXPlatformNodeDelegate,
       public WidgetObserver {
  public:
-  static NativeViewAccessibility* Create(View* view);
+  // A method for View to create a new NativeViewAccessibility instance for the
+  // given View. To retrieve the instance for |view|, use GetForView() instead.
+  static std::unique_ptr<NativeViewAccessibility> CreateForView(View* view);
+
+  ~NativeViewAccessibility() override;
 
   gfx::NativeViewAccessible GetNativeObject();
 
-  // 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
   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
   void OnWidgetDestroying(Widget* widget) override;
 
   Widget* parent_widget() const { return parent_widget_; }
   void SetParentWidget(Widget* parent_widget);
 
  protected:
   NativeViewAccessibility(View* view);
-  ~NativeViewAccessibility() override;
+
+  // Retrieves the NativeViewAccessibility instance for the given View. This
+  // invokes View::GetNativeViewAccessible() to ensure it exists.
+  static NativeViewAccessibility* GetForView(View* view);

[tapted, 2017/02/27 05:37:48]

Hm - this is the controversial bit that I was hoping to isolate in the other
CL... I don't think the change in views::View to make native_view_accessibility_
a std::unique_ptr relies on GetForView() (and that unique_ptr change is a good
change, that I don't think will be controversial at all).

[Patti Lor, 2017/03/03 02:55:54]

Done.

+
+  // Retrieves the gfx::NativeViewAccessibility for |view_|'s Widget/Rootview.
+  virtual gfx::NativeViewAccessible GetNativeViewAccessibleForWidget();
 
   // Weak. Owns this.
   View* view_;
 
   // Weak. Uses WidgetObserver to clear. This is set on the root view for
   // a widget that's owned by another widget, so we can walk back up the
   // tree.
   Widget* parent_widget_;
 
  private:
+  // Creates new platform-specific NativeViewAccessibility subclass instances.
+  static NativeViewAccessibility* Create(View* view);
+
   void PopulateChildWidgetVector(std::vector<Widget*>* result_child_widgets);
 
   // We own this, but it is reference-counted on some platforms so we can't use
   // a scoped_ptr. It is dereferenced in the destructor.
   ui::AXPlatformNode* ax_node_;
 
   ui::AXNodeData data_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeViewAccessibility);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_H_