Create a RenderProcess message class and move keygen to it.

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',
     '../components/tracing.gyp:tracing',
     '../gpu/command_buffer/command_buffer.gyp:gles2_utils',
     '../net/net.gyp:net',
@@ skipping 469 matching lines @@
       'common/plugin_list.cc',
       'common/plugin_list.h',
       'common/plugin_list_mac.mm',
       'common/plugin_list_posix.cc',
       'common/plugin_list_win.cc',
       'common/plugin_process_messages.h',
       'common/power_monitor_messages.h',
       'common/process_type.cc',
       'common/push_messaging_messages.h',
       'common/quota_messages.h',
+      'common/render_process_messages.h',
       'common/resource_messages.cc',
       'common/resource_messages.h',
       'common/resource_request_body.cc',
       'common/resource_request_body.h',
       'common/sandbox_init_mac.cc',
       'common/sandbox_init_mac.h',
       'common/sandbox_init_win.cc',
       'common/sandbox_linux/android/sandbox_bpf_base_policy_android.cc',
       'common/sandbox_linux/android/sandbox_bpf_base_policy_android.h',
       'common/sandbox_linux/bpf_cros_arm_gpu_policy_linux.cc',
@@ skipping 590 matching lines @@
         'common/gpu/client/gpu_memory_buffer_impl_ozone.cc',
         'common/gpu/client/gpu_memory_buffer_impl_ozone_native_pixmap.cc',
         'common/gpu/client/gpu_memory_buffer_impl_ozone_native_pixmap.h',
         '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',
       ],
     }],
   ],
 }