Implements a display scale tray setting behind a chrome switch

chrome/browser/flag_descriptions.h

 // Copyright 2017 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.
 
 #ifndef CHROME_BROWSER_FLAG_DESCRIPTIONS_H_
 #define CHROME_BROWSER_FLAG_DESCRIPTIONS_H_
 
 // Includes needed for macros allowing conditional compilation of some strings.
 #include "build/build_config.h"
 #include "build/buildflag.h"
@@ skipping 3373 matching lines @@
 extern const char kUseSuggestionsEvenIfFewFeatureDescription[];
 
 // Name of the about: flag for experimental location.reload() to trigger a
 // hard-reload.
 extern const char kLocationHardReloadName[];
 
 // Description of the about: flag for experimental location.reload() to trigger
 // a hard-reload.
 extern const char kLocationHardReloadDescription[];
 
+#if defined(OS_CHROMEOS) && defined(USE_ASH)
+// Name of the flag that enables system tray scale settings.
+extern const char kAshEnableScaleSettingsTrayName[];
+
+// Description of the flag that enables system tray scale settings.
+extern const char kAshEnableScaleSettingsTrayDescription[];
+#endif  // defined(OS_CHROMEOS) && defined(USE_ASH)
+
 }  // namespace flag_descriptions
 
 #endif  // CHROME_BROWSER_FLAG_DESCRIPTIONS_H_