Add IDL and stub implementation for chrome.usersPrivate API.

chrome/common/extensions/permissions/chrome_permission_message_rules.cc

 // 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.
 
 #include "chrome/common/extensions/permissions/chrome_permission_message_rules.h"
 
 #include "base/stl_util.h"
 #include "base/strings/string_util.h"
 #include "chrome/grit/generated_resources.h"
 #include "extensions/common/permissions/api_permission_set.h"
@@ skipping 489 matching lines @@
        {}},
       {IDS_EXTENSION_PROMPT_WARNING_SETTINGS_PRIVATE,
        {APIPermission::kSettingsPrivate},
        {}},
       {IDS_EXTENSION_PROMPT_WARNING_AUTOFILL_PRIVATE,
        {APIPermission::kAutofillPrivate},
        {}},
       {IDS_EXTENSION_PROMPT_WARNING_PASSWORDS_PRIVATE,
        {APIPermission::kPasswordsPrivate},
        {}},
+      {IDS_EXTENSION_PROMPT_WARNING_USERS_PRIVATE,
+       {APIPermission::kUsersPrivate},
+       {}},
 
       // Platform-app permission messages.
 
       // The permission string for "fileSystem" is only shown when
       // "write" or "directory" is present. Read-only access is only
       // granted after the user has been shown a file or directory
       // chooser dialog and selected a file or directory. Selecting
       // the file or directory is considered consent to read it.
       {IDS_EXTENSION_PROMPT_WARNING_FILE_SYSTEM_DIRECTORY,
        {APIPermission::kFileSystemDirectory},
@@ skipping 155 matching lines @@
   insert(permission_four);
   insert(permission_five);
   insert(permission_six);
 }
 
 ChromePermissionMessageRule::PermissionIDSetInitializer::
     ~PermissionIDSetInitializer() {
 }
 
 }  // namespace extensions