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

components/nacl/browser/nacl_broker_host_win.cc

Index: components/nacl/browser/nacl_broker_host_win.cc
diff --git a/components/nacl/browser/nacl_broker_host_win.cc b/components/nacl/browser/nacl_broker_host_win.cc
index 0f6302731ff24dc1866bae0562feb5cc2fa8a793..7c14f7c56996d031afa7dcadce684e4b4c7cbce2 100644
--- a/components/nacl/browser/nacl_broker_host_win.cc
+++ b/components/nacl/browser/nacl_broker_host_win.cc
@@ -25,9 +25,9 @@ class NaClBrokerSandboxedProcessLauncherDelegate
     : public content::SandboxedProcessLauncherDelegate {
  public:
   NaClBrokerSandboxedProcessLauncherDelegate() {}
-  virtual ~NaClBrokerSandboxedProcessLauncherDelegate() {}
+  ~NaClBrokerSandboxedProcessLauncherDelegate() override {}
 
-  virtual bool ShouldSandbox() override {
+  bool ShouldSandbox() override {
     return false;
   }