Remove docked windows entirely in M59.

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"
 
 namespace ash {
 namespace switches {
 
 // Note: If you add a switch, consider if it needs to be copied to a subsequent
 // command line if the process executes a new copy of itself.  (For example,
 // see chromeos::LoginUtil::GetOffTheRecordCommandLine().)
 
 // Please keep alphabetized.
 // TODO(sky): fix order!
 ASH_EXPORT extern const char kAshAnimateFromBootSplashScreen[];
 ASH_EXPORT extern const char kAshCopyHostBackgroundAtBoot[];
 ASH_EXPORT extern const char kAshDebugShortcuts[];
 ASH_EXPORT extern const char kAshDeveloperShortcuts[];
 ASH_EXPORT extern const char kAshDisableMaximizeModeWindowBackdrop[];
 ASH_EXPORT extern const char kAshDisableScreenOrientationLock[];
 ASH_EXPORT extern const char kAshDisableTouchExplorationMode[];
 ASH_EXPORT extern const char kAshEnableFullscreenAppList[];
 ASH_EXPORT extern const char kAshEnableMagnifierKeyScroller[];
 ASH_EXPORT extern const char kAshEnablePaletteOnAllDisplays[];
-ASH_EXPORT extern const char kAshEnableDockedWindows[];
 ASH_EXPORT extern const char kAshEnableTouchView[];
 ASH_EXPORT extern const char kAshEnableMirroredScreen[];
 ASH_EXPORT extern const char kAshForceEnablePalette[];
 ASH_EXPORT extern const char kAshHideNotificationsForFactory[];
 ASH_EXPORT extern const char kAshTouchHud[];
 ASH_EXPORT extern const char kAuraLegacyPowerButton[];
 
 // True if the pointer (cursor) position should be kept inside root windows.
 ASH_EXPORT bool ConstrainPointerToRoot();
 
-// True if docking windows right or left is enabled.
-ASH_EXPORT bool DockedWindowsEnabled();
-
 }  // namespace switches
 }  // namespace ash
 
 #endif  // ASH_COMMON_ASH_SWITCHES_H_