Do not activate system tray bubble by default

ash/common/wm_shell.h

 // Copyright 2016 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_WM_SHELL_H_
 #define ASH_COMMON_WM_SHELL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 29 matching lines @@
 }
 
 namespace ash {
 
 class AcceleratorController;
 class AccessibilityDelegate;
 class BrightnessControlDelegate;
 class FocusCycler;
 class ImmersiveContextAsh;
 class ImmersiveFullscreenController;
+class KeyEventWatcher;
 class KeyboardBrightnessControlDelegate;
 class KeyboardUI;
 class MaximizeModeController;
 class MruWindowTracker;
 class NewWindowDelegate;
 class PaletteDelegate;
 class ScopedDisableInternalMouseAndKeyboard;
 class SessionStateDelegate;
 class ShelfDelegate;
 class ShelfModel;
@@ skipping 241 matching lines @@
 
   virtual std::unique_ptr<WorkspaceEventHandler> CreateWorkspaceEventHandler(
       WmWindow* workspace_window) = 0;
 
   virtual std::unique_ptr<ScopedDisableInternalMouseAndKeyboard>
   CreateScopedDisableInternalMouseAndKeyboard() = 0;
 
   virtual std::unique_ptr<ImmersiveFullscreenController>
   CreateImmersiveFullscreenController() = 0;
 
+  virtual std::unique_ptr<KeyEventWatcher> CreateKeyEventWatcher() = 0;
+
   void CreateShelfDelegate();
 
   // Called after maximize mode has started, windows might still animate though.
   void OnMaximizeModeStarted();
 
   // Called after maximize mode has ended, windows might still be returning to
   // their original position.
   void OnMaximizeModeEnded();
 
   // Called when the overview mode is about to be started (before the windows
@@ skipping 148 matching lines @@
   scoped_refptr<base::SequencedWorkerPool> blocking_pool_;
 
 #if defined(OS_CHROMEOS)
   std::unique_ptr<LogoutConfirmationController> logout_confirmation_controller_;
 #endif
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_WM_SHELL_H_