Revert of Standardize usage of virtual/override/final in ipc/

ipc/mojo/ipc_channel_mojo.h

Index: ipc/mojo/ipc_channel_mojo.h
diff --git a/ipc/mojo/ipc_channel_mojo.h b/ipc/mojo/ipc_channel_mojo.h
index e5a4e335541c7f46d194290f2b88bb51b4aecc5c..b307fd49c6beee9b88705ec62237cb61fbc4c03d 100644
--- a/ipc/mojo/ipc_channel_mojo.h
+++ b/ipc/mojo/ipc_channel_mojo.h
@@ -87,21 +87,21 @@
   static scoped_ptr<ChannelFactory> CreateClientFactory(
       const ChannelHandle& channel_handle);
 
-  ~ChannelMojo() override;
+  virtual ~ChannelMojo();
 
   // ChannelMojoHost tells the client handle using this API.
   void OnClientLaunched(base::ProcessHandle handle);
 
   // Channel implementation
-  bool Connect() override;
-  void Close() override;
-  bool Send(Message* message) override;
-  base::ProcessId GetPeerPID() const override;
-  base::ProcessId GetSelfPID() const override;
+  virtual bool Connect() override;
+  virtual void Close() override;
+  virtual bool Send(Message* message) override;
+  virtual base::ProcessId GetPeerPID() const override;
+  virtual base::ProcessId GetSelfPID() const override;
 
 #if defined(OS_POSIX) && !defined(OS_NACL)
-  int GetClientFileDescriptor() const override;
-  base::ScopedFD TakeClientFileDescriptor() override;
+  virtual int GetClientFileDescriptor() const override;
+  virtual base::ScopedFD TakeClientFileDescriptor() override;
 
   // These access protected API of IPC::Message, which has ChannelMojo
   // as a friend class.
@@ -114,8 +114,9 @@
 #endif  // defined(OS_POSIX) && !defined(OS_NACL)
 
   // MojoBootstrapDelegate implementation
-  void OnPipeAvailable(mojo::embedder::ScopedPlatformHandle handle) override;
-  void OnBootstrapError() override;
+  virtual void OnPipeAvailable(
+      mojo::embedder::ScopedPlatformHandle handle) override;
+  virtual void OnBootstrapError() override;
 
   // Called from MessagePipeReader implementations
   void OnMessageReceived(Message& message);