Sort GYP and GN files under ppapi

ppapi/ppapi_proxy.gypi

 # Copyright (c) 2012 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.
 
 {
   'target_defaults': {
     'variables': {
       'ppapi_proxy_target': 0,
     },
     'target_conditions': [
@@ skipping 112 matching lines @@
           'proxy/plugin_resource_tracker.cc',
           'proxy/plugin_resource_tracker.h',
           'proxy/plugin_resource_var.cc',
           'proxy/plugin_resource_var.h',
           'proxy/plugin_var_serialization_rules.cc',
           'proxy/plugin_var_serialization_rules.h',
           'proxy/plugin_var_tracker.cc',
           'proxy/plugin_var_tracker.h',
           'proxy/ppapi_command_buffer_proxy.cc',
           'proxy/ppapi_command_buffer_proxy.h',
+          'proxy/ppapi_message_utils.h',
           'proxy/ppapi_messages.h',
-          'proxy/ppapi_message_utils.h',
           'proxy/ppb_audio_proxy.cc',
           'proxy/ppb_audio_proxy.h',
           'proxy/ppb_broker_proxy.cc',
           'proxy/ppb_broker_proxy.h',
           'proxy/ppb_buffer_proxy.cc',
           'proxy/ppb_buffer_proxy.h',
           'proxy/ppb_core_proxy.cc',
           'proxy/ppb_core_proxy.h',
           'proxy/ppb_flash_message_loop_proxy.cc',
           'proxy/ppb_flash_message_loop_proxy.h',
@@ skipping 150 matching lines @@
               'proxy/serialized_flash_menu.cc',
               'proxy/talk_resource.cc',
               'proxy/video_capture_resource.cc',
             ],
           }],
         ],
       }],
     ],
   },
 }