Move stash_backend into extensions/browser/mojo.

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 388 matching lines @@
       "install/crx_installer_error.h",
       "install/extension_install_ui.cc",
       "install/extension_install_ui.h",
       "install_flag.h",
       "lazy_background_task_queue.cc",
       "lazy_background_task_queue.h",
       "management_policy.cc",
       "management_policy.h",
       "mojo/keep_alive_impl.cc",
       "mojo/keep_alive_impl.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_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",
       "runtime_data.h",
       "script_execution_observer.h",
       "script_executor.cc",
       "script_executor.h",
-      "stash_backend.cc",
-      "stash_backend.h",
       "state_store.cc",
       "state_store.h",
       "suggest_permission_util.cc",
       "suggest_permission_util.h",
       "uninstall_reason.h",
       "update_observer.h",
       "updater/extension_cache.h",
       "updater/extension_downloader.cc",
       "updater/extension_downloader.h",
       "updater/extension_downloader_delegate.cc",
@@ skipping 51 matching lines @@
       ]
     }
   }
 
   if (is_win) {
     cflags = [
       "/wd4267", # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     ]
   }
 }