[Not Ready To Comimt] Add chrome://flags/#enable-off-main-thread-fetch

chrome/browser/flag_descriptions.h

 // 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.
 
 #ifndef CHROME_BROWSER_FLAG_DESCRIPTIONS_H_
 #define CHROME_BROWSER_FLAG_DESCRIPTIONS_H_
 
 // Includes needed for macros allowing conditional compilation of some strings.
 #include "build/build_config.h"
 #include "build/buildflag.h"
@@ skipping 87 matching lines @@
 
 // Description for the flag to set parameters for No-State Prefetch.
 extern const char kNostatePrefetchDescription[];
 
 // Name for the flag to set parameters for Speculative Prefetch
 extern const char kSpeculativePrefetchName[];
 
 // Description for the flag to set parameters for Speculative Prefetch.
 extern const char kSpeculativePrefetchDescription[];
 
+// Name for experimental resource fetch optimizations for workers.
+extern const char kOffMainThreadFetchName[];
+
+// Description for experimental resource fetch optimizations for workers.
+extern const char kOffMainThreadFetchDescription[];
+
 //  Force Tablet Mode
 
 // Name for the flag to force tablet mode.
 extern const char kForceTabletModeName[];
 
 // Description for the flag to force tablet mode.
 extern const char kForceTabletModeDescription[];
 
 // Description of the TouchView mode. In TouchView mode, the keyboard can flip
 // behind the screen so the Chromebook operates like a tablet computer.
@@ skipping 3044 matching lines @@
 
 // Description of the about: flag enabling emoji, handwriting and voice input on
 // opt-in IME menu.
 extern const char kEnableEhvInputDescription[];
 
 #endif  // #if defined(OS_CHROMEOS)
 
 }  // namespace flag_descriptions
 
 #endif  // CHROME_BROWSER_FLAG_DESCRIPTIONS_H_