MacViews a11y: Sync VoiceOver cursor with keyboard focus.

ui/views/view.h

Index: ui/views/view.h
diff --git a/ui/views/view.h b/ui/views/view.h
index 6b45c6313baf3bee9f08047d3891e28b35de22d1..0be90f3e5a0960008c59a912c48a1e1ca1b8217e 100644
--- a/ui/views/view.h
+++ b/ui/views/view.h
@@ -945,6 +945,10 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
 
   // Accessibility -------------------------------------------------------------
 
+  // Gets the NativeViewAccessibility instance for this view, and creates one if
+  // it doesn't yet exist.
+  NativeViewAccessibility* GetNativeViewAccessibility();

[tapted, 2016/09/26 05:19:18]

I'm unsure about this - we'll have to see what views OWNERS say. E.g. it's a bit
confusing having bith GetNativeViewAccessibility() and
GetNativeViewAccessible(). An alternative could be something like

  AXPlatformNodeCocoa root = hostedView_->GetNativeViewAccessible();
  AXPlatformNodeDelegate* delegate = [root getDelegate];  // Needs an
implementation of getDelegate.
  return delegate->GetFocus();

[Patti Lor, 2016/09/28 00:29:14]

I like your alternative, but I think it needs to be cross-platform - I use this
a lot in some of my other CLs (e.g. ignoring accessibility elements, see
https://codereview.chromium.org/2119413004/diff/100001/ui/views/accessibility...
if you want context). Is it gross to have NativeViewAccessibility keep a static
reference to all the instances? Or maybe just change the previously mentioned CL
etc to work for Mac-only?

[dmazzoni, 2016/09/29 16:06:15]

For context, the reason I didn't add GetNativeViewAccessibility() before was
that GetNativeViewAccessible() doesn't always return something based on
NativeViewAccessibility. In particular, WebView and NativeViewHost both
return something different.

So my first inclination is to try to keep that design.

See other comment.

[Patti Lor, 2016/10/04 05:45:14]

Ok, thanks for the context. I've deleted the changes to view.* for this CL since
they're no longer needed, and will investigate alternatives for use in my other
accessibility CLs.

+
   // Modifies |state| to reflect the current accessible state of this view.
   virtual void GetAccessibleState(ui::AXViewState* state) { }