Create the PruneCrashReportsThread in the handler.

handler/handler.gyp

 # Copyright 2014 The Crashpad Authors. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 20 matching lines @@
         '../third_party/mini_chromium/mini_chromium.gyp:base',
         '../tools/tools.gyp:crashpad_tool_support',
         '../util/util.gyp:crashpad_util',
       ],
       'include_dirs': [
         '..',
       ],
       'sources': [
         'crash_report_upload_thread.cc',
         'crash_report_upload_thread.h',
+        'handler_main.cc',
+        'handler_main.h',
         'mac/crash_report_exception_handler.cc',
         'mac/crash_report_exception_handler.h',
         'mac/exception_handler_server.cc',
         'mac/exception_handler_server.h',
-        'handler_main.cc',
-        'handler_main.h',
+        'prune_crash_reports_thread.cc',
+        'prune_crash_reports_thread.h',
         'win/crash_report_exception_handler.cc',
         'win/crash_report_exception_handler.h',
       ],
     },
     {
       'target_name': 'crashpad_handler',
       'type': 'executable',
       'dependencies': [
         '../third_party/mini_chromium/mini_chromium.gyp:base',
         '../tools/tools.gyp:crashpad_tool_support',
@@ skipping 89 matching lines @@
               ],
             },
           ],
         }],
       ],
     }, {
       'targets': [],
     }],
   ],
 }