Standardize usage of virtual/override/final in components/

components/nacl/loader/nacl_listener.cc

Index: components/nacl/loader/nacl_listener.cc
diff --git a/components/nacl/loader/nacl_listener.cc b/components/nacl/loader/nacl_listener.cc
index 6eb3c14c9521db76f6ee8d225fd0f5b53a880d35..8562a28eafce479b2307d2db4cfa919c5aded039 100644
--- a/components/nacl/loader/nacl_listener.cc
+++ b/components/nacl/loader/nacl_listener.cc
@@ -163,7 +163,7 @@ class BrowserValidationDBProxy : public NaClValidationDB {
       : listener_(listener) {
   }
 
-  virtual bool QueryKnownToValidate(const std::string& signature) override {
+  bool QueryKnownToValidate(const std::string& signature) override {
     // Initialize to false so that if the Send fails to write to the return
     // value we're safe.  For example if the message is (for some reason)
     // dispatched as an async message the return parameter will not be written.
@@ -176,7 +176,7 @@ class BrowserValidationDBProxy : public NaClValidationDB {
     return result;
   }
 
-  virtual void SetKnownToValidate(const std::string& signature) override {
+  void SetKnownToValidate(const std::string& signature) override {
     // Caching is optional: NaCl will still work correctly if the IPC fails.
     if (!listener_->Send(new NaClProcessMsg_SetKnownToValidate(signature))) {
       LOG(ERROR) << "Failed to update NaCl validation cache.";
@@ -186,8 +186,9 @@ class BrowserValidationDBProxy : public NaClValidationDB {
   // This is the "old" code path for resolving file tokens. It's only
   // used for resolving the main nexe.
   // TODO(teravest): Remove this.
-  virtual bool ResolveFileToken(struct NaClFileToken* file_token,
-                                int32* fd, std::string* path) override {
+  bool ResolveFileToken(struct NaClFileToken* file_token,
+                        int32* fd,
+                        std::string* path) override {
     *fd = -1;
     *path = "";
     if (!NaClFileTokenIsValid(file_token)) {
@@ -262,7 +263,7 @@ bool NaClListener::Send(IPC::Message* msg) {
 // NaClChromeMainAppStart(), so it can't be used for servicing messages.
 class FileTokenMessageFilter : public IPC::MessageFilter {
  public:
-  virtual bool OnMessageReceived(const IPC::Message& msg) override {
+  bool OnMessageReceived(const IPC::Message& msg) override {
     bool handled = true;
     IPC_BEGIN_MESSAGE_MAP(FileTokenMessageFilter, msg)
       IPC_MESSAGE_HANDLER(NaClProcessMsg_ResolveFileTokenAsyncReply,
@@ -281,7 +282,7 @@ class FileTokenMessageFilter : public IPC::MessageFilter {
     g_listener->OnFileTokenResolved(token_lo, token_hi, ipc_fd, file_path);
   }
  private:
-  virtual ~FileTokenMessageFilter() { }
+  ~FileTokenMessageFilter() override {}
 };
 
 void NaClListener::Listen() {