views/mus: Install a mus-friend ContextFactory for tests.

mash/BUILD.gn

 # Copyright 2015 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/nacl/config.gni")
 import("//services/catalog/public/tools/catalog.gni")
 import("//services/service_manager/public/service_manifest.gni")
 import("//testing/test.gni")
 
 # Target that builders build.
@@ skipping 107 matching lines @@
       "//ash/mus:resources",
       "//ash/mus:unittests",
       "//base",
       "//base/test:test_support",
       "//cc",
       "//cc:test_support",
       "//cc/surfaces",
       "//mojo/edk/system",
       "//services/catalog:lib",
       "//ui/aura",
+      "//ui/aura:test_support",
       "//ui/base",
       "//ui/compositor:test_support",
       "//ui/gl:test_support",
     ]
     data_deps = [
       ":mash_unittests_catalog_copy",
       "//ash/mus:resources",
     ]
   }
 
@@ skipping 14 matching lines @@
     testonly = true
     sources = get_target_outputs(":mash_unittests_catalog")
     outputs = [
       "${root_out_dir}/mash_unittests_catalog.json",
     ]
     deps = [
       ":mash_unittests_catalog",
     ]
   }
 }