Fix -Wnon-virtual-dtor compiler warnings.

This is done by explicitly adding a virtual dtor to interface classes,
since the cost is small given that there are already virtual functions.

The exceptions are for classes that have a Release() or Delete() method,
in which case it is non-virtual and protected to indicate that the virtual
class is never the deletion point.

BUG=
R=brucedawson@chromium.org, thestig@chromium.org

Review URL: https://codereview.chromium.org/810883005

1 files changed, 1 insertions, 0 deletions

diff --git a/fpdfsdk/include/pdfwindow/PWL_IconList.h b/fpdfsdk/include/pdfwindow/PWL_IconList.h
index effabd0713..6b3d577504 100644
--- a/fpdfsdk/include/pdfwindow/PWL_IconList.h
+++ b/fpdfsdk/include/pdfwindow/PWL_IconList.h
@@ -16,6 +16,7 @@ class CPWL_Label;
 class IPWL_IconList_Notify
 {
 public:
+        virtual ~IPWL_IconList_Notify() { }
 	virtual void						OnNoteListSelChanged(FX_INT32 nItemIndex) = 0;
 };