Add other variations (with ids) for NTPSnippets to chrome://flags

ios/chrome/browser/about_flags.mm

 // Copyright 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.
 
 // Implementation of about_flags for iOS that sets flags based on experimental
 // settings.
 
 #include "ios/chrome/browser/about_flags.h"
 
 #include <stddef.h>
@@ skipping 242 matching lines @@
 }  // namespace
 
 void ConvertFlagsToSwitches(flags_ui::FlagsStorage* flags_storage,
                             base::CommandLine* command_line) {
   FlagsStateSingleton::GetFlagsState()->ConvertFlagsToSwitches(
       flags_storage, command_line, flags_ui::kAddSentinels,
       switches::kEnableIOSFeatures, switches::kDisableIOSFeatures);
   AppendSwitchesFromExperimentalSettings(command_line);
 }
 
+std::vector<std::string> RegisterAllFeatureVariationParameters(
+    flags_ui::FlagsStorage* flags_storage,
+    base::FeatureList* feature_list) {
+  return FlagsStateSingleton::GetFlagsState()
+      ->RegisterAllFeatureVariationParameters(flags_storage, feature_list);
+}
+
 void GetFlagFeatureEntries(flags_ui::FlagsStorage* flags_storage,
                            flags_ui::FlagAccess access,
                            base::ListValue* supported_entries,
                            base::ListValue* unsupported_entries) {
   FlagsStateSingleton::GetFlagsState()->GetFlagFeatureEntries(
       flags_storage, access, supported_entries, unsupported_entries,
       base::Bind(&SkipConditionalFeatureEntry));
 }
 
 void SetFeatureEntryEnabled(flags_ui::FlagsStorage* flags_storage,
                             const std::string& internal_name,
                             bool enable) {
   FlagsStateSingleton::GetFlagsState()->SetFeatureEntryEnabled(
       flags_storage, internal_name, enable);
 }
 
 void ResetAllFlags(flags_ui::FlagsStorage* flags_storage) {
   FlagsStateSingleton::GetFlagsState()->ResetAllFlags(flags_storage);
 }
 
 namespace testing {
 
 const flags_ui::FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing