Use a new flag to control showing "DOWNLOAD PAGE LATER" in error pages

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 1629 matching lines @@
      IDS_FLAGS_PROGRESS_BAR_ANIMATION_DESCRIPTION, kOsAndroid,
      MULTI_VALUE_TYPE(kProgressBarAnimationChoices)},
     {"progress-bar-completion", IDS_FLAGS_PROGRESS_BAR_COMPLETION_NAME,
      IDS_FLAGS_PROGRESS_BAR_COMPLETION_DESCRIPTION, kOsAndroid,
      MULTI_VALUE_TYPE(kProgressBarCompletionChoices)},
 #endif  // OS_ANDROID
 #if defined(OS_ANDROID)
     {"offline-bookmarks", IDS_FLAGS_OFFLINE_BOOKMARKS_NAME,
      IDS_FLAGS_OFFLINE_BOOKMARKS_DESCRIPTION, kOsAndroid,
      FEATURE_VALUE_TYPE(offline_pages::kOfflineBookmarksFeature)},
+    {"offline-pages-async-download",
+     IDS_FLAGS_OFFLINE_PAGES_ASYNC_DOWNLOAD_NAME,
+     IDS_FLAGS_OFFLINE_PAGES_ASYNC_DOWNLOAD_DESCRIPTION, kOsAndroid,
+     FEATURE_VALUE_TYPE(offline_pages::kOfflinePagesAsyncDownloadFeature)},
     {"offline-pages-background-loading",
      IDS_FLAGS_OFFLINE_PAGES_BACKGROUND_LOADING_NAME,
      IDS_FLAGS_OFFLINE_PAGES_BACKGROUND_LOADING_DESCRIPTION, kOsAndroid,
      FEATURE_VALUE_TYPE(offline_pages::kOfflinePagesBackgroundLoadingFeature)},
     {"offline-pages-sharing", IDS_FLAGS_OFFLINE_PAGES_SHARING_NAME,
      IDS_FLAGS_OFFLINE_PAGES_SHARING_DESCRIPTION, kOsAndroid,
      FEATURE_VALUE_TYPE(offline_pages::kOfflinePagesSharingFeature)},
     {"background-loader-for-downloads",
      IDS_FLAGS_BACKGROUND_LOADER_FOR_DOWNLOADS_NAME,
      IDS_FLAGS_BACKGROUND_LOADER_FOR_DOWNLOADS_DESCRIPTION, kOsAndroid,
@@ skipping 638 matching lines @@
 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
 
 const FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags