Add switch to enable palette tray UI.

ash/common/ash_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.
 
 #ifndef ASH_COMMON_ASH_SWITCHES_H_
 #define ASH_COMMON_ASH_SWITCHES_H_
 
 #include "ash/ash_export.h"
 
 #include "build/build_config.h"
@@ skipping 11 matching lines @@
 ASH_EXPORT extern const char kAshCopyHostBackgroundAtBoot[];
 ASH_EXPORT extern const char kAshDebugShortcuts[];
 ASH_EXPORT extern const char kAshDisableMaximizeModeWindowBackdrop[];
 #if defined(OS_CHROMEOS)
 ASH_EXPORT extern const char kAshDisableScreenOrientationLock[];
 #endif
 ASH_EXPORT extern const char kAshDisableTouchExplorationMode[];
 #if defined(OS_CHROMEOS)
 ASH_EXPORT extern const char kAshEnableFullscreenAppList[];
 ASH_EXPORT extern const char kAshEnableMagnifierKeyScroller[];
+ASH_EXPORT extern const char kAshEnablePalette[];
 ASH_EXPORT extern const char kAshEnableUnifiedDesktop[];
 #endif
 ASH_EXPORT extern const char kAshEnableTouchView[];
 ASH_EXPORT extern const char kAshEnableMirroredScreen[];
 ASH_EXPORT extern const char kAshDisableStableOverviewOrder[];
 ASH_EXPORT extern const char kAshEnableStableOverviewOrder[];
 ASH_EXPORT extern const char kAshEnableSoftwareMirroring[];
 ASH_EXPORT extern const char kAshEnableTouchViewTesting[];
 ASH_EXPORT extern const char kAshEnableWindowCycleUi[];
 ASH_EXPORT extern const char kAshHideNotificationsForFactory[];
@@ skipping 14 matching lines @@
 
 #if defined(OS_CHROMEOS)
 // True if the pointer (cursor) position should be kept inside root windows.
 ASH_EXPORT bool ConstrainPointerToRoot();
 #endif
 
 }  // namespace switches
 }  // namespace ash
 
 #endif  // ASH_COMMON_ASH_SWITCHES_H_