Add handle waiting to StashBackend.

extensions/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("//testing/test.gni")
 import("//tools/grit/grit_rule.gni")
 import("//tools/grit/repack.gni")
 
 assert(enable_extensions)
 
@@ skipping 274 matching lines @@
       "//extensions/common",
       "//extensions/renderer",
       "//extensions/strings",
       "//mojo/environment:chromium",
       "//testing/gmock",
       "//testing/gtest",
       "//third_party/leveldatabase",
       "//third_party/mojo/src/mojo/edk/js",
       "//third_party/mojo/src/mojo/edk/system",
       "//third_party/mojo/src/mojo/public/cpp/bindings",
+      "//third_party/mojo/src/mojo/public/interfaces/application",
     ]
 
     if (is_win) {
       deps += [ "//base/allocator" ]
     }
   }
 }
 
 test("extensions_browsertests") {
   sources = [
@@ skipping 49 matching lines @@
   ]
 
   if (is_win) {
     deps += [ "//base/allocator" ]
   }
 
   if (is_mac) {
     deps += [ "shell:app_shell" ]  # Needed for App Shell.app's Helper.
   }
 }