Extract ProcessManager from ExtensionSystem.

extensions/browser/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 
 # GYP version: extensions/extensions.gyp:extensions_browser
 source_set("browser") {
   sources = [
@@ skipping 397 matching lines @@
       "mojo/keep_alive_impl.h",
       "mojo/service_registration_manager.cc",
       "mojo/service_registration_manager.h",
       "mojo/stash_backend.cc",
       "mojo/stash_backend.h",
       "pref_names.cc",
       "pref_names.h",
       "process_manager.cc",
       "process_manager.h",
       "process_manager_delegate.h",
+      "process_manager_factory.cc",
+      "process_manager_factory.h",
       "process_manager_observer.h",
       "process_map.cc",
       "process_map.h",
       "process_map_factory.cc",
       "process_map_factory.h",
       "quota_service.cc",
       "quota_service.h",
       "renderer_startup_helper.cc",
       "renderer_startup_helper.h",
       "runtime_data.cc",
@@ skipping 65 matching lines @@
       ]
     }
   }
 
   if (is_win) {
     cflags = [
       "/wd4267", # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     ]
   }
 }