Set focusibility correctly when initializing a window in mus+ash.

ui/views/widget/widget.h

Index: ui/views/widget/widget.h
diff --git a/ui/views/widget/widget.h b/ui/views/widget/widget.h
index a9861ec27b214d7b3efcb0e64fbe3a9505e852a7..33c065643f1cfb6ce82f3dff3b9e4f2ef367b338 100644
--- a/ui/views/widget/widget.h
+++ b/ui/views/widget/widget.h
@@ -214,6 +214,10 @@ class VIEWS_EXPORT Widget : public internal::NativeWidgetDelegate,
     InitParams(const InitParams& other);
     ~InitParams();
 
+    // Returns the activatablity based on |activatable|, but also handles the
+    // case where |activatable| is |ACTIVATABLE_DEFAULT|.
+    bool CanActivate() const;
+
     Type type;
     // If null, a default implementation will be constructed. The default
     // implementation deletes itself when the Widget closes.