[Print Preview] Re-add flags for register promos

chrome/common/chrome_switches.h

 // Copyright (c) 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.
 
 // Defines all the command-line switches used by Chrome.
 
 #ifndef CHROME_COMMON_CHROME_SWITCHES_H_
 #define CHROME_COMMON_CHROME_SWITCHES_H_
 
 #include "build/build_config.h"
@@ skipping 188 matching lines @@
 extern const char kEnableOriginChipLeadingLocationBar[];
 extern const char kEnableOriginChipTrailingLocationBar[];
 extern const char kEnableOriginChipLeadingMenuButton[];
 extern const char kEnableOriginChipV2[];
 extern const char kEnableOriginChipV2HideOnMouseRelease[];
 extern const char kEnableOriginChipV2HideOnUserInput[];
 extern const char kEnablePanels[];
 extern const char kEnablePasswordAutofillPublicSuffixDomainMatching[];
 extern const char kEnablePermissionsBubbles[];
 extern const char kEnableQueryExtraction[];
+extern const char kEnablePrintPreviewRegisterPromos[];
 extern const char kEnablePrivetStorage[];
 extern const char kEnableProfiling[];
 extern const char kEnableQuic[];
 extern const char kEnableQuicHttps[];
 extern const char kEnableQuicPacing[];
 extern const char kEnableQuicPortSelection[];
 extern const char kEnableResourceContentSettings[];
 extern const char kEnableSavePasswordBubble[];
 extern const char kEnableSdch[];
 extern const char kEnableSearchButtonInOmniboxAlways[];
@@ skipping 255 matching lines @@
 #else
 extern const char kEnablePrintPreview[];
 #endif
 
 // DON'T ADD RANDOM STUFF HERE. Put it in the main section above in
 // alphabetical order, or in one of the ifdefs (also in order in each section).
 
 }  // namespace switches
 
 #endif  // CHROME_COMMON_CHROME_SWITCHES_H_