Allow features to refer to subkeys in _manifest_features.json.

chrome/common/extensions/manifest_tests/extension_manifests_platformapp_unittest.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/common/extensions/manifest_tests/extension_manifest_test.h"
 
 #include "base/command_line.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/scoped_temp_dir.h"
 #include "chrome/common/chrome_switches.h"
@@ skipping 12 matching lines @@
   LoadAndExpectSuccess("init_valid_platform_app.json");
 
   LoadAndExpectError(
       "init_invalid_platform_app_1.json",
       extension_manifest_errors::kLaunchNotAllowedForPlatformApps);
   LoadAndExpectError(
       "init_invalid_platform_app_2.json",
       extension_manifest_errors::kBackgroundRequiredForPlatformApps);
   LoadAndExpectError(
       "init_invalid_platform_app_3.json",
-      "Feature 'platform_app' is not accessible. "
-          "'platform_app' requires manifest version of at least 2.");
+      "'platform_app' requires manifest version of at least 2.");
 }
 
 TEST_F(ExtensionManifestTest, CertainApisRequirePlatformApps) {
   // Put APIs here that should be restricted to platform apps, but that haven't
   // yet graduated from experimental.
   const char* kPlatformAppExperimentalApis[] = {
     "dns",
     "serial",
     "socket",
   };
@@ skipping 47 matching lines @@
 
   // Finally, we should succeed with both experimental and platform-app flags
   // set.
   CommandLine::ForCurrentProcess()->AppendSwitch(switches::kEnablePlatformApps);
   for (size_t i = 0; i < arraysize(kPlatformAppExperimentalApis); ++i) {
     const char* api_name = kPlatformAppExperimentalApis[i];
     FilePath file_path = temp_dir.path().AppendASCII(api_name);
     LoadAndExpectSuccess(file_path.MaybeAsASCII().c_str());
   }
 }