[NTP Snippets] Make a base::Feature instead of raw cmdline flag

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 1792 matching lines @@
     {"enable-audio-support-for-desktop-share",
      IDS_FLAG_ENABLE_AUDIO_FOR_DESKTOP_SHARE,
      IDS_FLAG_ENABLE_AUDIO_FOR_DESKTOP_SHARE_DESCRIPTION,
      kOsAll,
      SINGLE_VALUE_TYPE(switches::kEnableAudioSupportForDesktopShare)},
 #if defined(ENABLE_EXTENSIONS)
     {"enable-tab-for-desktop-share", IDS_FLAG_ENABLE_TAB_FOR_DESKTOP_SHARE,
      IDS_FLAG_ENABLE_TAB_FOR_DESKTOP_SHARE_DESCRIPTION, kOsAll,
      SINGLE_VALUE_TYPE(extensions::switches::kEnableTabForDesktopShare)}
 #endif
+#if defined(OS_ANDROID)
+    {"enable-ntp-snippets", IDS_FLAGS_ENABLE_NTP_SNIPPETS_NAME,
+     IDS_FLAGS_ENABLE_NTP_SNIPPETS_DESCRIPTION, kOsAndroid,
+     FEATURE_VALUE_TYPE(chrome::android::kNTPSnippetsFeature)},
+#endif  // defined(OS_ANDROID)
     // NOTE: Adding new command-line switches requires adding corresponding
     // entries to enum "LoginCustomFlags" in histograms.xml. See note in
     // histograms.xml and don't forget to run AboutFlagsHistogramTest unit test.
 };
 
 class FlagsStateSingleton {
  public:
   FlagsStateSingleton()
       : flags_state_(kFeatureEntries, arraysize(kFeatureEntries)) {}
   ~FlagsStateSingleton() {}
@@ skipping 201 matching lines @@
 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
 
 const FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags