Remove pepper_messages.h.

content/content_common.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.
 
 {
   'dependencies': [
     '../base/base.gyp:base',
     '../cc/cc.gyp:cc',
     '../cc/ipc/cc_ipc.gyp:cc_ipc',
     '../components/tracing.gyp:tracing',
@@ skipping 434 matching lines @@
       'common/origin_trials/trial_token.h',
       'common/origin_trials/trial_token_validator.cc',
       'common/origin_trials/trial_token_validator.h',
       'common/origin_util.cc',
       'common/p2p_messages.h',
       'common/page_state_serialization.cc',
       'common/page_state_serialization.h',
       'common/page_zoom.cc',
       'common/pepper_file_util.cc',
       'common/pepper_file_util.h',
-      'common/pepper_messages.h',
       'common/pepper_plugin_list.cc',
       'common/pepper_plugin_list.h',
       'common/pepper_renderer_instance_data.cc',
       'common/pepper_renderer_instance_data.h',
       'common/platform_notification_messages.h',
       'common/plugin_list.cc',
       'common/plugin_list.h',
       'common/power_monitor_messages.h',
       'common/process_type.cc',
       'common/push_messaging_messages.h',
@@ skipping 132 matching lines @@
       ],
     }],
     ['enable_plugins==1', {
       'dependencies': [
         '../ppapi/ppapi_internal.gyp:ppapi_shared',
       ],
     }, {  # enable_plugins == 0
       'sources!': [
         'common/pepper_file_util.cc',
         'common/pepper_file_util.h',
-        'common/pepper_messages.h',
         'common/pepper_plugin_list.cc',
         'common/pepper_plugin_list.h',
         'common/pepper_renderer_instance_data.cc',
         'common/pepper_renderer_instance_data.h',
         'common/plugin_list.cc',
         'common/plugin_list.h',
         'public/common/pepper_plugin_info.cc',
         'public/common/pepper_plugin_info.h',
       ],
     }],
@@ skipping 38 matching lines @@
       'sources!': [
         'common/cursors/webcursor_ozone.cc',
         'common/font_list_ozone.cc',
         'common/gpu/gpu_memory_buffer_factory_ozone.cc',
         'common/gpu/gpu_memory_buffer_factory_ozone_native_pixmap.cc',
         'common/gpu/gpu_memory_buffer_factory_ozone_native_pixmap.h',
       ],
     }],
   ],
 }