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

chrome/browser/about_flags.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/browser/about_flags.h"
 
 #include <iterator>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 2521 matching lines @@
      FEATURE_VALUE_TYPE(chrome::android::kCustomFeedbackUi)},
 #endif  // OS_ANDROID
 
     {"enable-resource-prefetch", flag_descriptions::kSpeculativePrefetchName,
      flag_descriptions::kSpeculativePrefetchDescription, kOsAll,
      FEATURE_WITH_PARAMS_VALUE_TYPE(
          predictors::kSpeculativeResourcePrefetchingFeature,
          kSpeculativeResourcePrefetchingFeatureVariations,
          "SpeculativeResourcePrefetchingValidation")},
 
+    {"enable-off-main-thread-fetch", flag_descriptions::kOffMainThreadFetchName,
+     flag_descriptions::kOffMainThreadFetchDescription, kOsAll,
+     FEATURE_VALUE_TYPE(features::kOffMainThreadFetch)},
+
 #if defined(OS_MACOSX)
     {"tab-strip-keyboard-focus", flag_descriptions::kTabStripKeyboardFocusName,
      flag_descriptions::kTabStripKeyboardFocusDescription, kOsMac,
      FEATURE_VALUE_TYPE(features::kTabStripKeyboardFocus)},
 #endif
 
 #if defined(OS_CHROMEOS)
     {"enable-chromevox-arc-support",
      flag_descriptions::kEnableChromevoxArcSupportName,
      flag_descriptions::kEnableChromevoxArcSupportDescription, kOsCrOS,
@@ skipping 240 matching lines @@
 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
 
 const FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags