mash: Migrate wallpaper controllers to ash/common.

ash/common/accelerators/accelerator_controller.cc

Index: ash/common/accelerators/accelerator_controller.cc
diff --git a/ash/common/accelerators/accelerator_controller.cc b/ash/common/accelerators/accelerator_controller.cc
index 339f230e8ff8e04918a09c55c55f27ca8877195b..c7c4e6e2fa99a199b51877aafa73a41dd9e4c092 100644
--- a/ash/common/accelerators/accelerator_controller.cc
+++ b/ash/common/accelerators/accelerator_controller.cc
@@ -744,6 +744,7 @@ bool AcceleratorController::CanPerformAction(
     case DEBUG_PRINT_LAYER_HIERARCHY:
     case DEBUG_PRINT_VIEW_HIERARCHY:
     case DEBUG_PRINT_WINDOW_HIERARCHY:
+    case DEBUG_TOGGLE_WALLPAPER_MODE:
       return debug::DebugAcceleratorsEnabled();
     case NEW_INCOGNITO_WINDOW:
       return CanHandleNewIncognitoWindow();
@@ -856,6 +857,7 @@ void AcceleratorController::PerformAction(AcceleratorAction action,
     case DEBUG_PRINT_LAYER_HIERARCHY:
     case DEBUG_PRINT_VIEW_HIERARCHY:
     case DEBUG_PRINT_WINDOW_HIERARCHY:
+    case DEBUG_TOGGLE_WALLPAPER_MODE:
       debug::PerformDebugActionIfEnabled(action);
       break;
     case EXIT: