Revert of Move content's shell connections to the IO thread

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 96 matching lines @@
       'public/common/child_process_host.h',
       'public/common/child_process_host_delegate.cc',
       'public/common/child_process_host_delegate.h',
       'public/common/child_process_sandbox_support_linux.h',
       'public/common/color_suggestion.cc',
       'public/common/color_suggestion.h',
       'public/common/common_param_traits.cc',
       'public/common/common_param_traits.h',
       'public/common/common_param_traits_macros.h',
       'public/common/console_message_level.h',
-      'public/common/connection_filter.h',
       'public/common/content_client.cc',
       'public/common/content_client.h',
       'public/common/content_constants.cc',
       'public/common/content_constants.h',
       'public/common/content_descriptors.h',
       'public/common/content_features.cc',
       'public/common/content_features.h',
       'public/common/content_ipc_logging.h',
       'public/common/content_paths.h',
       'public/common/content_switches.cc',
@@ skipping 533 matching lines @@
       ],
     }],
     ['enable_ipc_fuzzer==1', {
       'sources': [
         'common/external_ipc_dumper.cc',
         'common/external_ipc_dumper.h',
       ],
     }],
   ],
 }