Update {virtual,override} to follow C++11 style in ppapi.

ppapi/proxy/output_protection_resource.h

Index: ppapi/proxy/output_protection_resource.h
diff --git a/ppapi/proxy/output_protection_resource.h b/ppapi/proxy/output_protection_resource.h
index 6b80b9108089db0a2cc9b1a62779aed936906247..25dcc53e0c032e32165d372e50fca092b6dbaa10 100644
--- a/ppapi/proxy/output_protection_resource.h
+++ b/ppapi/proxy/output_protection_resource.h
@@ -22,18 +22,17 @@ class OutputProtectionResource
                            PP_Instance instance);
 
  private:
-  virtual ~OutputProtectionResource();
+  ~OutputProtectionResource() override;
 
   // PluginResource overrides.
-  virtual thunk::PPB_OutputProtection_API* AsPPB_OutputProtection_API()
-      override;
+  thunk::PPB_OutputProtection_API* AsPPB_OutputProtection_API() override;
 
   // PPB_OutputProtection_API implementation.
-  virtual int32_t QueryStatus(
+  int32_t QueryStatus(
       uint32_t* link_mask,
       uint32_t* protection_mask,
       const scoped_refptr<TrackedCallback>& callback) override;
-  virtual int32_t EnableProtection(
+  int32_t EnableProtection(
       uint32_t desired_method_mask,
       const scoped_refptr<TrackedCallback>& callback) override;