Convert SerialIoHandler to use buffer interfaces for I/O API methods.

device/serial/serial.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 26 matching lines @@
         '../../mojo/mojo_base.gyp:mojo_cpp_bindings',
         '../../net/net.gyp:net',
       ],
       'export_dependent_settings': [
         'device_serial_mojo',
         '../../mojo/mojo_base.gyp:mojo_cpp_bindings',
       ],
       'sources': [
         '<(SHARED_INTERMEDIATE_DIR)/device/serial/serial.mojom.cc',
         '<(SHARED_INTERMEDIATE_DIR)/device/serial/serial.mojom.h',
+        'buffer.cc',
+        'buffer.h',
         'serial_connection.cc',
         'serial_connection.h',
         'serial_connection_factory.cc',
         'serial_connection_factory.h',
         'serial_device_enumerator.cc',
         'serial_device_enumerator.h',
         'serial_device_enumerator_linux.cc',
         'serial_device_enumerator_linux.h',
         'serial_device_enumerator_mac.cc',
         'serial_device_enumerator_mac.h',
@@ skipping 17 matching lines @@
         'device_serial',
         'device_serial_mojo',
       ],
       'sources': [
         'test_serial_io_handler.cc',
         'test_serial_io_handler.h',
       ],
     },
   ],
 }