add a flag to enable/disable download interception on android

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 760 matching lines @@
 #if defined(OS_CHROMEOS)
     {"network-portal-notification", IDS_FLAGS_NETWORK_PORTAL_NOTIFICATION_NAME,
      IDS_FLAGS_NETWORK_PORTAL_NOTIFICATION_DESCRIPTION, kOsCrOS,
      ENABLE_DISABLE_VALUE_TYPE(
          chromeos::switches::kEnableNetworkPortalNotification,
          chromeos::switches::kDisableNetworkPortalNotification)},
 #endif
     {"enable-download-resumption", IDS_FLAGS_DOWNLOAD_RESUMPTION_NAME,
      IDS_FLAGS_DOWNLOAD_RESUMPTION_DESCRIPTION, kOsAll,
      FEATURE_VALUE_TYPE(features::kDownloadResumption)},
+#if defined(OS_ANDROID)
+    {"enable-system-download-manager",
+     IDS_FLAGS_ENABLE_SYSTEM_DOWNLOAD_MANAGER_NAME,
+     IDS_FLAGS_ENABLE_SYSTEM_DOWNLOAD_MANAGER_DESCRIPTION,
+     kOsAndroid,
+     FEATURE_VALUE_TYPE(chrome::android::kSystemDownloadManager)},
+#endif
 #if defined(OS_CHROMEOS)
     {"download-notification", IDS_FLAGS_DOWNLOAD_NOTIFICATION_NAME,
      IDS_FLAGS_DOWNLOAD_NOTIFICATION_DESCRIPTION, kOsCrOS,
      SINGLE_DISABLE_VALUE_TYPE(switches::kDisableDownloadNotification)},
 #endif
 #if defined(ENABLE_PLUGINS)
     {"allow-nacl-socket-api", IDS_FLAGS_ALLOW_NACL_SOCKET_API_NAME,
      IDS_FLAGS_ALLOW_NACL_SOCKET_API_DESCRIPTION, kOsDesktop,
      SINGLE_VALUE_TYPE_AND_VALUE(switches::kAllowNaClSocketAPI, "*")},
 #endif
@@ skipping 1240 matching lines @@
 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
 
 const FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags