Standardize usage of virtual/override/final in ipc/

ipc/ipc_send_fds_test.cc

Index: ipc/ipc_send_fds_test.cc
diff --git a/ipc/ipc_send_fds_test.cc b/ipc/ipc_send_fds_test.cc
index 3961fa16e52d73bf234d80ab6167b5c2cd7e5bdd..cf2c68003de7ce723ea28b17c354ea8cea153911 100644
--- a/ipc/ipc_send_fds_test.cc
+++ b/ipc/ipc_send_fds_test.cc
@@ -33,7 +33,7 @@ const char* kDevZeroPath = "/dev/zero";
 
 class MyChannelDescriptorListenerBase : public IPC::Listener {
  public:
-  virtual bool OnMessageReceived(const IPC::Message& message) override {
+  bool OnMessageReceived(const IPC::Message& message) override {
     PickleIterator iter(message);
 
     base::FileDescriptor descriptor;
@@ -60,12 +60,12 @@ class MyChannelDescriptorListener : public MyChannelDescriptorListenerBase {
     return num_fds_received_ == kNumFDsToSend;
   }
 
-  virtual void OnChannelError() override {
+  void OnChannelError() override {
     base::MessageLoop::current()->Quit();
   }
 
  protected:
-  virtual void HandleFD(int fd) override {
+  void HandleFD(int fd) override {
     // Check that we can read from the FD.
     char buf;
     ssize_t amt_read = read(fd, &buf, 1);
@@ -202,9 +202,7 @@ class MyCBListener : public MyChannelDescriptorListenerBase {
     }
 
  protected:
-  virtual void HandleFD(int fd) override {
-    cb_.Run(fd);
-  }
+  void HandleFD(int fd) override { cb_.Run(fd); }
  private:
   base::Callback<void(int)> cb_;
 };