Remove the iOS QR Code scanner experiment code.

ios/chrome/browser/chrome_switches.cc

Index: ios/chrome/browser/chrome_switches.cc
diff --git a/ios/chrome/browser/chrome_switches.cc b/ios/chrome/browser/chrome_switches.cc
index 2f92cc5afa70e9abf97fac60813cf145e62549ed..9b0f375d7bcf0c4846d64174d3986af20aaff867 100644
--- a/ios/chrome/browser/chrome_switches.cc
+++ b/ios/chrome/browser/chrome_switches.cc
@@ -40,9 +40,6 @@ 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";
 
@@ -90,9 +87,6 @@ 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";