Add about:flags entry for Mac V2 sandbox.

chrome/browser/flag_descriptions.cc

 // Copyright 2017 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/browser/flag_descriptions.h"
 
 namespace flag_descriptions {
 
 const char kBrowserSideNavigationName[] = "Enable browser side navigation";
 
@@ skipping 1454 matching lines @@
 #if defined(OS_MACOSX)
 
 const char kAppInfoDialogName[] = "Toolkit-Views App Info Dialog.";
 
 const char kAppInfoDialogDescription[] =
     "Makes the Toolkit-Views based App Info dialog accessible from "
     "chrome://apps or chrome://extensions in place of the native extension "
     "permissions dialog, or the details link (which is a link to the Web "
     "Store).";
 
+const char kMacV2SandboxName[] = "Mac V2 Sandbox";
+
+const char kMacV2SandboxDescription[] =
+    "Eliminates the unsandboxed warmup phase and sandboxes processes for their "
+    "entire life cycle.";
+
 const char kMacViewsNativeAppWindowsName[] = "Toolkit-Views App Windows.";
 
 const char kMacViewsNativeAppWindowsDescription[] =
     "Controls whether to use Toolkit-Views based Chrome App windows.";
 
 const char kMacViewsTaskManagerName[] = "Toolkit-Views Task Manager.";
 
 const char kMacViewsTaskManagerDescription[] =
     "Controls whether to use the Toolkit-Views based Task Manager.";
 
@@ skipping 1760 matching lines @@
     "in non-sticky mode (do not change work area in non-sticky mode).";
 
 const char kUiDevToolsName[] = "Enable native UI inspection";
 const char kUiDevToolsDescription[] =
     "Enables inspection of native UI elements. For local inspection use "
     "chrome://inspect#other";
 
 #endif  // defined(OS_CHROMEOS)
 
 }  // namespace flag_descriptions