Revert of 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 332a631068e55e2a355d0c60a7999041afe23ae8..3961fa16e52d73bf234d80ab6167b5c2cd7e5bdd 100644
--- a/ipc/ipc_send_fds_test.cc
+++ b/ipc/ipc_send_fds_test.cc
@@ -33,7 +33,7 @@
 
 class MyChannelDescriptorListenerBase : public IPC::Listener {
  public:
-  bool OnMessageReceived(const IPC::Message& message) override {
+  virtual bool OnMessageReceived(const IPC::Message& message) override {
     PickleIterator iter(message);
 
     base::FileDescriptor descriptor;
@@ -60,10 +60,12 @@
     return num_fds_received_ == kNumFDsToSend;
   }
 
-  void OnChannelError() override { base::MessageLoop::current()->Quit(); }
+  virtual void OnChannelError() override {
+    base::MessageLoop::current()->Quit();
+  }
 
  protected:
-  void HandleFD(int fd) override {
+  virtual void HandleFD(int fd) override {
     // Check that we can read from the FD.
     char buf;
     ssize_t amt_read = read(fd, &buf, 1);
@@ -200,7 +202,9 @@
     }
 
  protected:
-  void HandleFD(int fd) override { cb_.Run(fd); }
+  virtual void HandleFD(int fd) override {
+    cb_.Run(fd);
+  }
  private:
   base::Callback<void(int)> cb_;
 };