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

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 ec1e0dbe626e0f256b985e9d75acd184515b5687..a87d81168f993c74bac683175294507b06fd94d6 100644
--- a/ui/views/accessibility/native_view_accessibility.h
+++ b/ui/views/accessibility/native_view_accessibility.h
@@ -42,7 +42,9 @@ class VIEWS_EXPORT NativeViewAccessibility
     : public ui::AXPlatformNodeDelegate,
       public WidgetObserver {
  public:
-  static std::unique_ptr<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;
 
@@ -75,6 +77,10 @@ class VIEWS_EXPORT NativeViewAccessibility
  protected:
   explicit NativeViewAccessibility(View* view);
 
+  // Retrieves the NativeViewAccessibility instance for the given View. This
+  // invokes View::GetNativeViewAccessible() to ensure it exists.
+  static NativeViewAccessibility* GetForView(View* view);
+
   // Weak. Owns this.
   View* view_;
 
@@ -84,6 +90,9 @@ class VIEWS_EXPORT NativeViewAccessibility
   Widget* parent_widget_;
 
  private:
+  // Creates new platform-specific NativeViewAccessibility subclass instances.
+  static NativeViewAccessibility* Create(View* view);

[tapted, 2017/03/06 01:43:09]

Do we need this? (i.e. Why can't we use the current `Create` that returns a
unique_ptr -- it looks like only CreateForView calls it.

Note if we don't need a version that returns a raw pointer, we probably don't
need to rename Create to CreateForView either)

[Patti Lor, 2017/03/13 03:03:26]

You're right, it looks like we don't need this any more :O Previously I had it
there to avoid some code duplication, but now CreateForView is short we can get
rid of it - thanks! Fixed, leaving it just as Create() now.

+
   void PopulateChildWidgetVector(std::vector<Widget*>* result_child_widgets);
 
   // We own this, but it is reference-counted on some platforms so we can't use