[gtkmm] Gtk::Window: Make raise() non-virtual

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 7da8a91ae79e67b4cd54ebd0ca76cffca6940d6c
Author: Kjell Ahlstedt <kjell ahlstedt bredband net>
Date:   Mon Nov 14 10:42:54 2016 +0100

    Gtk::Window: Make raise() non-virtual
    
    and make some comments in menushell.ccg and window.ccg clearer.

 gtk/src/menushell.ccg |    5 ++++-
 gtk/src/window.ccg    |    2 +-
 gtk/src/window.hg     |    3 +--
 3 files changed, 6 insertions(+), 4 deletions(-)
---
diff --git a/gtk/src/menushell.ccg b/gtk/src/menushell.ccg
index c236782..be5775b 100644
--- a/gtk/src/menushell.ccg
+++ b/gtk/src/menushell.ccg
@@ -42,7 +42,10 @@ MenuShell::MenuShell(GtkMenuShell* castitem)
   accel_window_ (nullptr)
 {}
 
-// TODO: Why do we need a custom dtor?
+// Why do we need a custom dtor?
+// We don't actually need it, but a gmmproc-generated destructor calls destroy_().
+// That's unnecessary here. GtkMenuShell is an abstract base class. When ~MenuShell()
+// is executed, destroy_() has already been called by the destructor of a subclass.
 MenuShell::~MenuShell() noexcept
 {}
 
diff --git a/gtk/src/window.ccg b/gtk/src/window.ccg
index 7a71720..20da4aa 100644
--- a/gtk/src/window.ccg
+++ b/gtk/src/window.ccg
@@ -55,7 +55,7 @@ void Window::destroy_()
 {
   //Called from destructors.
   //overridden so that the correct _release_c_instance() ends up being called by the destructor.
-  //destroy_() is virtual, but _release_c_instance() is not.
+  //The destructors that call destroy_() are virtual, but _release_c_instance() is not.
 
   //GTKMM_LIFECYCLE
 
diff --git a/gtk/src/window.hg b/gtk/src/window.hg
index 3665e76..611f40d 100644
--- a/gtk/src/window.hg
+++ b/gtk/src/window.hg
@@ -350,11 +350,10 @@ dnl
    */
   Glib::RefPtr<AccelGroup> get_accel_group();
 
-  //TODO: Remove the virtual from this when we can break ABI.
   /** Brings the window to the front.
    * This is just a more obvious convenience wrapper for get_window()->raise().
    */
-  virtual void raise();
+  void raise();
 
   ///Overriden to warn that it doesn't make sense to use Gtk::manage() on this class because it has no 
parent container.
   void set_manage() override;