Add chrome://flags/#browser-side-navigation

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";
+
+const char kBrowserSideNavigationDescription[] =
+    "Enable browser side navigation (aka PlzNaviate).";
+
 //  Material Design version of chrome://bookmarks
 
 const char kEnableMaterialDesignBookmarksName[] =
     "Enable Material Design bookmarks";
 
 const char kEnableMaterialDesignBookmarksDescription[] =
     "If enabled, the chrome://bookmarks/ URL loads the Material Design "
     "bookmarks page.";
 
 //  Material Design version of chrome://policy
@@ skipping 3186 matching lines @@
 
 const char kDisableNewVirtualKeyboardBehaviorName[] =
     "New window behavior for the accessibility keyboard";
 const char kDisableNewVirtualKeyboardBehaviorDescription[] =
     "Disable new window behavior for the accessibility keyboard "
     "in non-sticky mode (do not change work area in non-sticky mode).";
 
 #endif  // defined(OS_CHROMEOS)
 
 }  // namespace flag_descriptions