Mark overridden destructors with 'override' and remove 'virtual'

This silences a new warning in clang 5.0

Change-Id: Ieb5b75a6ffed60107c3fd16075d2ecfd515b55e8
Reviewed-on: https://skia-review.googlesource.com/10006
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/gm/image.cpp b/gm/image.cpp
index 43e3a0bd21..f672e07ed1 100644
--- a/gm/image.cpp
+++ b/gm/image.cpp
@@ -114,7 +114,7 @@ public:
         fSize.set(SkIntToScalar(W), SkIntToScalar(H));
     }
 
-    virtual ~ImageGM() {
+    ~ImageGM() override {
         sk_free(fBuffer);
     }