Fix another virtual specifier.

mojo/services/html_viewer/ax_provider_impl_unittest.cc

Index: mojo/services/html_viewer/ax_provider_impl_unittest.cc
diff --git a/mojo/services/html_viewer/ax_provider_impl_unittest.cc b/mojo/services/html_viewer/ax_provider_impl_unittest.cc
index 7e7c5ec00b0046f646abaa69e54f7db45ae522c9..6e488ef5a0f8a40bf2692e106bbb31166443f137 100644
--- a/mojo/services/html_viewer/ax_provider_impl_unittest.cc
+++ b/mojo/services/html_viewer/ax_provider_impl_unittest.cc
@@ -52,7 +52,7 @@ class AxProviderImplTest : public testing::Test {
     blink::initialize(new html_viewer::BlinkPlatformImpl());
   }
 
-  virtual ~AxProviderImplTest() override { blink::shutdown(); }
+  ~AxProviderImplTest() override { blink::shutdown(); }
 
  private:
   base::MessageLoopForUI message_loop;