cros: Use runtime stylus detection for ash palette.

chrome/browser/ui/ash/palette_delegate_chromeos.h

 // Copyright 2015 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_UI_ASH_PALETTE_DELEGATE_CHROMEOS_H_
 #define CHROME_BROWSER_UI_ASH_PALETTE_DELEGATE_CHROMEOS_H_
 
 #include <string>
 
 #include "ash/common/palette_delegate.h"
 #include "ash/common/session/session_state_observer.h"
 #include "base/callback_list.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/values.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
-#include "ui/events/devices/input_device_event_observer.h"
 
 class PrefChangeRegistrar;
 class Profile;
 
 namespace ash {
 class ScopedSessionStateObserver;
 }
 
 namespace chromeos {
 
 // A class which allows the Ash palette to perform chrome actions.
 class PaletteDelegateChromeOS : public ash::PaletteDelegate,
-                                public ui::InputDeviceEventObserver,
                                 public ash::SessionStateObserver,
                                 public content::NotificationObserver {
  public:
-  // Attempts to create a palette delegate. This will return null if the palette
-  // feature is not enabled.
-  static std::unique_ptr<PaletteDelegateChromeOS> Create();
-
+  PaletteDelegateChromeOS();
   ~PaletteDelegateChromeOS() override;
 
  private:
-  PaletteDelegateChromeOS();
-
   // ash::PaletteDelegate:
   std::unique_ptr<EnableListenerSubscription> AddPaletteEnableListener(
       const EnableListener& on_state_changed) override;
   void CreateNote() override;
   bool HasNoteApp() override;
-  void SetStylusStateChangedCallback(
-      const OnStylusStateChangedCallback& on_stylus_state_changed) override;
   bool ShouldAutoOpenPalette() override;
   bool ShouldShowPalette() override;
   void TakeScreenshot() override;
   void TakePartialScreenshot(const base::Closure& done) override;
   void CancelPartialScreenshot() override;
 
   // ash::SessionStateObserver:
   void ActiveUserChanged(const AccountId& account_id) override;
 
   // content::NotificationObserver:
   void Observe(int type,
                const content::NotificationSource& source,
                const content::NotificationDetails& details) override;
 
-  // ui::InputDeviceObserver:
-  void OnStylusStateChanged(ui::StylusState state) override;
-
   // Called when the palette enabled pref has changed.
   void OnPaletteEnabledPrefChanged();
 
   void SetProfile(Profile* profile);
   void OnPartialScreenshotDone(const base::Closure& then);
 
   base::CallbackList<void(bool)> palette_enabled_callback_list_;
-  OnStylusStateChangedCallback on_stylus_state_changed_;
 
   // Unowned pointer to the active profile.
   Profile* profile_ = nullptr;
   std::unique_ptr<PrefChangeRegistrar> pref_change_registrar_;
   std::unique_ptr<ash::ScopedSessionStateObserver> session_state_observer_;
   content::NotificationRegistrar registrar_;
 
   base::WeakPtrFactory<PaletteDelegateChromeOS> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PaletteDelegateChromeOS);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_UI_ASH_PALETTE_DELEGATE_CHROMEOS_H_