ash/chromeos: Add shift-alt-p shortcut to open 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"
@@ skipping 13 matching lines @@
 }
 
 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:
-  PaletteDelegateChromeOS();
+  // Attempts to create a palette delegate. This will return null if the palette
+  // feature is not enabled.
+  static std::unique_ptr<PaletteDelegateChromeOS> Create();
+
   ~PaletteDelegateChromeOS() override;
 
  private:
+  PaletteDelegateChromeOS();
+
   // ash::PaletteDelegate:
   std::unique_ptr<EnableListenerSubscription> AddPaletteEnableListener(
       const EnableListener& on_state_changed) override;
   void CreateNote() override;
   bool HasNoteApp() override;
   void SetPartialMagnifierState(bool enabled) override;
   void SetStylusStateChangedCallback(
       const OnStylusStateChangedCallback& on_stylus_state_changed) override;
   bool ShouldAutoOpenPalette() override;
+  bool ShouldShowPalette() override;
   void TakeScreenshot() override;
   void TakePartialScreenshot() 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;
@@ skipping 14 matching lines @@
   std::unique_ptr<PrefChangeRegistrar> pref_change_registrar_;
   std::unique_ptr<ash::ScopedSessionStateObserver> session_state_observer_;
   content::NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(PaletteDelegateChromeOS);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_UI_ASH_PALETTE_DELEGATE_CHROMEOS_H_