Add some includes to make it more explicit. (This was breaking under some changes I have locally to minimize include graph without this). Also fixes a gcc 2.7.2.3 issue.

widget/src/xlib/nsComboBox.h

@@ -21,6 +21,7 @@
 
 #include "nsWidget.h"
 #include "nsIComboBox.h"
+#include "nsIListWidget.h"
 
 class nsComboBox : public nsWidget,
                    public nsIListWidget,

widget/src/xlib/nsListBox.h

@@ -21,6 +21,7 @@
 
 #include "nsWidget.h"
 #include "nsIListBox.h"
+#include "nsIListWidget.h"
 
 /**
  * Native Win32 Listbox wrapper

widget/src/xlib/nsMenu.h

@@ -22,8 +22,8 @@
 #include "nsWidget.h"
 #include "nsIMenu.h"
 #include "nsISupportsArray.h"
+#include "nsIMenuListener.h"
 
-class nsIMenuListener;
 
 /**
  * Native Win32 button wrapper

widget/src/xlib/nsWidget.cpp

@@ -20,6 +20,9 @@
 #include "nsIXlibWindowService.h"
 
 #include "nsWidget.h"
+#include "nsIEventListener.h"
+#include "nsIMenuListener.h"
+#include "nsIMouseListener.h"
 #include "nsGfxCIID.h"
 
 #include "xlibrgb.h"