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

ppapi/proxy/device_enumeration_resource_helper_unittest.cc

Index: ppapi/proxy/device_enumeration_resource_helper_unittest.cc
diff --git a/ppapi/proxy/device_enumeration_resource_helper_unittest.cc b/ppapi/proxy/device_enumeration_resource_helper_unittest.cc
index a8fa24c1ecfe6ef9003cd2e358b03d8c3af3370d..32bc68a0dde8d4332cdbb28a2cfbe6987a0ec10f 100644
--- a/ppapi/proxy/device_enumeration_resource_helper_unittest.cc
+++ b/ppapi/proxy/device_enumeration_resource_helper_unittest.cc
@@ -71,10 +71,10 @@ class TestResource : public PluginResource {
         device_enumeration_(this) {
   }
 
-  virtual ~TestResource() {}
+  ~TestResource() override {}
 
-  virtual void OnReplyReceived(const ResourceMessageReplyParams& params,
-                               const IPC::Message& msg) override {
+  void OnReplyReceived(const ResourceMessageReplyParams& params,
+                       const IPC::Message& msg) override {
     if (!device_enumeration_.HandleReply(params, msg))
       PluginResource::OnReplyReceived(params, msg);
   }