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

ios/chrome/browser/chrome_switches.cc

 // Copyright 2015 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 "ios/chrome/browser/chrome_switches.h"
 
 namespace switches {
 
 // -----------------------------------------------------------------------------
 // When commenting your switch, please use the same voice as surrounding
@@ skipping 19 matching lines @@
 // view when focused on form fields.
 const char kDisableIOSPasswordSuggestions[] =
     "disable-ios-password-suggestions";
 
 // Disable the snapshots lru cache.
 const char kDisableLRUSnapshotCache[] = "disable-lru-snapshot-cache";
 
 // Disable auto-reload of error pages if offline.
 const char kDisableOfflineAutoReload[] = "disable-offline-auto-reload";
 
-// Disable the Payment Request API.
-const char kDisablePaymentRequest[] = "disable-payment-request";
-
 // Disables the tab strip auto scroll new tabs.
 const char kDisableTabStripAutoScrollNewTabs[] =
     "disable-tab-strip-autoscroll-new-tabs";
 
 // Disables Physical Web scanning for nearby URLs.
 const char kDisableIOSPhysicalWeb[] = "disable-ios-physical-web";
 
 // Disables Request Mobile Site.
 const char kDisableRequestMobileSite[] = "disable-request-mobile-site";
 
@@ skipping 28 matching lines @@
 
 // Enable password generation for iOS.
 const char kEnableIOSPasswordGeneration[] = "enable-ios-password-generation";
 
 // Enables the snapshot lru cache.
 const char kEnableLRUSnapshotCache[] = "enable-lru-snapshot-cache";
 
 // Enable auto-reload of error pages if offline.
 const char kEnableOfflineAutoReload[] = "enable-offline-auto-reload";
 
-// Enable the Payment Request API.
-const char kEnablePaymentRequest[] = "enable-payment-request";
-
 // Enables context-sensitive reader mode button in the toolbar.
 const char kEnableReaderModeToolbarIcon[] = "enable-reader-mode-toolbar-icon";
 
 // Enables the Spotlight actions.
 const char kEnableSpotlightActions[] = "enable-spotlight-actions";
 
 // Enables Physical Web scanning for nearby URLs.
 const char kEnableIOSPhysicalWeb[] = "enable-ios-physical-web";
 
 // Enables the Suggestions UI
@@ skipping 21 matching lines @@
 const char kIOSHostResolverRules[] = "host-resolver-rules";
 
 // Ignores certificate-related errors.
 const char kIOSIgnoreCertificateErrors[] = "ignore-certificate-errors";
 
 // Allows for forcing socket connections to http/https to use fixed ports.
 const char kIOSTestingFixedHttpPort[] = "testing-fixed-http-port";
 const char kIOSTestingFixedHttpsPort[] = "testing-fixed-https-port";
 
 }  // namespace switches