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 2c5ba165dd74f95145584a07675811d383f3064d..fa553c37c665961220dfc3fb82a55a497d480a68 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.