Remove the iOS QR Code scanner experiment code.

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 22 matching lines @@
 
 // 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 QR Code scanner.
-const char kDisableQRScanner[] = "disable-qr-scanner";
-
 // Disables the Spotlight actions.
 const char kDisableSpotlightActions[] = "disable-spotlight-actions";
 
 // Disables the tab strip auto scroll new tabs.
 const char kDisableTabStripAutoScrollNewTabs[] =
     "disable-tab-strip-autoscroll-new-tabs";
 
 // Disables the tab switcher.
 const char kDisableTabSwitcher[] = "disable-tab-switcher";
 
@@ skipping 27 matching lines @@
 
 // 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 the QR Code scanner.
-const char kEnableQRScanner[] = "enable-qr-scanner";
-
 // 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 the tab switcher.
 const char kEnableTabSwitcher[] = "enable-tab-switcher";
 
 // Enables Physical Web scanning for nearby URLs.
@@ skipping 27 matching lines @@
 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";
 
 // Enables grouping websites by domain and filtering them by period.
 const char kHistoryEnableGroupByDomain[] = "enable-grouped-history";
 
 }  // namespace switches