Remove the iOS QR Code scanner experiment code.

ios/chrome/browser/app_startup_parameters.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.
 
 #import "ios/chrome/browser/app_startup_parameters.h"
 
 #include "base/logging.h"
-#include "ios/chrome/browser/experimental_flags.h"
 #import "ios/chrome/browser/xcallback_parameters.h"
 #include "url/gurl.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 @implementation AppStartupParameters {
   GURL _externalURL;
   BOOL _launchVoiceSearch;
@@ skipping 31 matching lines @@
 
 - (NSString*)description {
   return [NSString stringWithFormat:@"ExternalURL: %s \nXCallbackParams: %@",
                                     _externalURL.spec().c_str(),
                                     _xCallbackParameters];
 }
 
 #pragma mark Property implementation.
 
 - (BOOL)launchQRScanner {
-  return _launchQRScanner && experimental_flags::IsQRCodeReaderEnabled();
+  return _launchQRScanner;
 }
 
 - (void)setLaunchQRScanner:(BOOL)launch {
   _launchQRScanner = launch;
 }
 
 @end