Delete the GTK+ port of Chrome.

content/content_child.gypi

 # Copyright 2013 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',
     '../components/tracing.gyp:tracing',
     '../skia/skia.gyp:skia',
     '../ui/base/ui_base.gyp:ui_base',
@@ skipping 98 matching lines @@
     'child/npapi/plugin_url_fetcher.h',
     'child/npapi/plugin_web_event_converter_mac.h',
     'child/npapi/plugin_web_event_converter_mac.mm',
     'child/npapi/webplugin.h',
     'child/npapi/webplugin_accelerated_surface_mac.h',
     'child/npapi/webplugin_delegate.h',
     'child/npapi/webplugin_delegate_impl.cc',
     'child/npapi/webplugin_delegate_impl.h',
     'child/npapi/webplugin_delegate_impl_android.cc',
     'child/npapi/webplugin_delegate_impl_aura.cc',
-    'child/npapi/webplugin_delegate_impl_gtk.cc',
     'child/npapi/webplugin_delegate_impl_mac.mm',
     'child/npapi/webplugin_delegate_impl_win.cc',
     'child/npapi/webplugin_ime_win.cc',
     'child/npapi/webplugin_ime_win.h',
     'child/npapi/webplugin_resource_client.h',
     'child/plugin_message_generator.cc',
     'child/plugin_message_generator.h',
     'child/plugin_messages.h',
     'child/plugin_param_traits.cc',
     'child/plugin_param_traits.h',
@@ skipping 157 matching lines @@
         }, {
           'dependencies': [
             '../third_party/nss/nss.gyp:nspr',
             '../third_party/nss/nss.gyp:nss',
           ],
         }],
       ],
     }],
   ],
 }