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

ipc/ipc_channel_nacl.h

Index: ipc/ipc_channel_nacl.h
diff --git a/ipc/ipc_channel_nacl.h b/ipc/ipc_channel_nacl.h
index 9c1e80fb10fea3c7a57d1520549fed01134bdd32..f0649b2602228a8670b91bff3e3870fc2fb08a16 100644
--- a/ipc/ipc_channel_nacl.h
+++ b/ipc/ipc_channel_nacl.h
@@ -38,14 +38,14 @@ class ChannelNacl : public Channel,
   ChannelNacl(const IPC::ChannelHandle& channel_handle,
               Mode mode,
               Listener* listener);
-  virtual ~ChannelNacl();
+  ~ChannelNacl() override;
 
   // Channel implementation.
-  virtual base::ProcessId GetPeerPID() const override;
-  virtual base::ProcessId GetSelfPID() const override;
-  virtual bool Connect() override;
-  virtual void Close() override;
-  virtual bool Send(Message* message) override;
+  base::ProcessId GetPeerPID() const override;
+  base::ProcessId GetSelfPID() const override;
+  bool Connect() override;
+  void Close() override;
+  bool Send(Message* message) override;
 
   // Posted to the main thread by ReaderThreadRunner.
   void DidRecvMsg(scoped_ptr<MessageContents> contents);
@@ -59,12 +59,12 @@ class ChannelNacl : public Channel,
   void CallOnChannelConnected();
 
   // ChannelReader implementation.
-  virtual ReadState ReadData(char* buffer,
-                             int buffer_len,
-                             int* bytes_read) override;
-  virtual bool WillDispatchInputMessage(Message* msg) override;
-  virtual bool DidEmptyInputBuffers() override;
-  virtual void HandleInternalMessage(const Message& msg) override;
+  ReadState ReadData(char* buffer,
+                     int buffer_len,
+                     int* bytes_read) override;
+  bool WillDispatchInputMessage(Message* msg) override;
+  bool DidEmptyInputBuffers() override;
+  void HandleInternalMessage(const Message& msg) override;
 
   Mode mode_;
   bool waiting_connect_;