[Payments] Add an entry for Payment Request to chrome://flags on iOS

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>
 #include <stdint.h>
 #import <UIKit/UIKit.h>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/singleton.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/sys_info.h"
 #include "base/task_scheduler/switches.h"
 #include "components/dom_distiller/core/dom_distiller_switches.h"
 #include "components/flags_ui/feature_entry.h"
 #include "components/flags_ui/feature_entry_macros.h"
 #include "components/flags_ui/flags_storage.h"
 #include "components/flags_ui/flags_ui_switches.h"
 #include "components/ntp_tiles/switches.h"
+#include "components/payments/core/features.h"
 #include "components/security_state/core/switches.h"
 #include "components/signin/core/common/signin_switches.h"
 #include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/chrome_switches.h"
 #include "ios/chrome/browser/ios_chrome_flag_descriptions.h"
 #include "ios/chrome/grit/ios_strings.h"
 #include "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 #include "ios/web/public/user_agent.h"
 #include "ios/web/public/web_view_creation_util.h"
 
@@ skipping 43 matching lines @@
      flag_descriptions::kPhysicalWebDescription, flags_ui::kOsIos,
      ENABLE_DISABLE_VALUE_TYPE(switches::kEnableIOSPhysicalWeb,
                                switches::kDisableIOSPhysicalWeb)},
     {"browser-task-scheduler", flag_descriptions::kBrowserTaskScheduler,
      flag_descriptions::kBrowserTaskSchedulerDescription, flags_ui::kOsIos,
      ENABLE_DISABLE_VALUE_TYPE(switches::kEnableBrowserTaskScheduler,
                                switches::kDisableBrowserTaskScheduler)},
     {"mark-non-secure-as", flag_descriptions::kMarkHttpAsName,
      flag_descriptions::kMarkHttpAsDescription, flags_ui::kOsIos,
      MULTI_VALUE_TYPE(kMarkHttpAsChoices)},
+    {"web-payments", flag_descriptions::kWebPaymentsName,
+     flag_descriptions::kWebPaymentsDescription, flags_ui::kOsIos,
+     FEATURE_VALUE_TYPE(payments::features::kWebPayments)},
 };
 
 // Add all switches from experimental flags to |command_line|.
 void AppendSwitchesFromExperimentalSettings(base::CommandLine* command_line) {
   NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
 
   // Populate command line flag for the tab strip auto scroll new tabs
   // experiment from the configuration plist.
   if ([defaults boolForKey:@"TabStripAutoScrollNewTabsDisabled"])
     command_line->AppendSwitch(switches::kDisableTabStripAutoScrollNewTabs);
@@ skipping 94 matching lines @@
     int32_t major = 0;
     int32_t minor = 0;
     int32_t bugfix = 0;
     base::SysInfo::OperatingSystemVersionNumbers(&major, &minor, &bugfix);
     std::string product = base::StringPrintf("Version/%d.%d", major, minor);
 
     command_line->AppendSwitchASCII(switches::kUserAgent,
                                     web::BuildUserAgentFromProduct(product));
   }
 
-  // Populate command line flag for the Payment Request API.
-  NSString* enable_payment_request =
-      [defaults stringForKey:@"EnablePaymentRequest"];
-  if ([enable_payment_request isEqualToString:@"Enabled"]) {
-    command_line->AppendSwitch(switches::kEnablePaymentRequest);
-  } else if ([enable_payment_request isEqualToString:@"Disabled"]) {
-    command_line->AppendSwitch(switches::kDisablePaymentRequest);
-  }
-
   // Populate command line flag for Suggestions UI display.
   NSString* enableSuggestions = [defaults stringForKey:@"EnableSuggestions"];
   if ([enableSuggestions isEqualToString:@"Enabled"]) {
     command_line->AppendSwitch(switches::kEnableSuggestionsUI);
   } else if ([enableSuggestions isEqualToString:@"Disabled"]) {
     command_line->AppendSwitch(switches::kDisableSuggestionsUI);
   }
 
   // Populate command line flag for fetching missing favicons for NTP tiles.
   NSString* enableMostLikelyFaviconsFromServer =
@@ skipping 135 matching lines @@
 }
 
 namespace testing {
 
 const flags_ui::FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing