Implement permission_broker for serial devices.

device/serial/serial_io_handler_posix.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef DEVICE_SERIAL_SERIAL_IO_HANDLER_POSIX_H_
 #define DEVICE_SERIAL_SERIAL_IO_HANDLER_POSIX_H_
 
 #include "base/message_loop/message_loop.h"
 #include "device/serial/serial_io_handler.h"
 
 namespace device {
 
 class SerialIoHandlerPosix : public SerialIoHandler,
                              public base::MessageLoopForIO::Watcher {
  protected:
   // SerialIoHandler impl.
   virtual void ReadImpl() override;
   virtual void WriteImpl() override;
   virtual void CancelReadImpl() override;
   virtual void CancelWriteImpl() override;
   virtual bool Flush() const override;
   virtual serial::DeviceControlSignalsPtr GetControlSignals() const override;
   virtual bool SetControlSignals(
       const serial::HostControlSignals& control_signals) override;
   virtual bool ConfigurePort(const serial::ConnectionOptions& options) override;
   virtual serial::ConnectionInfoPtr GetPortInfo() const override;
+  virtual void RequestAccess(
+      const std::string& port,
+      scoped_refptr<base::MessageLoopProxy> io_message_loop) override;
   virtual bool PostOpen() override;
 
  private:
   friend class SerialIoHandler;
 
   SerialIoHandlerPosix(
       scoped_refptr<base::MessageLoopProxy> file_thread_message_loop);
   virtual ~SerialIoHandlerPosix();
 
   // base::MessageLoopForIO::Watcher implementation.
   virtual void OnFileCanWriteWithoutBlocking(int fd) override;
   virtual void OnFileCanReadWithoutBlocking(int fd) override;
 
   void EnsureWatchingReads();
   void EnsureWatchingWrites();
 
   base::MessageLoopForIO::FileDescriptorWatcher file_read_watcher_;
   base::MessageLoopForIO::FileDescriptorWatcher file_write_watcher_;
 
   // Flags indicating if the message loop is watching the device for IO events.
   bool is_watching_reads_;
   bool is_watching_writes_;
 
   DISALLOW_COPY_AND_ASSIGN(SerialIoHandlerPosix);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_SERIAL_SERIAL_IO_HANDLER_POSIX_H_