Enabled/disable touch screen in TabletPowerButtonController

ash/common/shell_delegate.h

Index: ash/common/shell_delegate.h
diff --git a/ash/common/shell_delegate.h b/ash/common/shell_delegate.h
index 27d59cff49f0f1b6b4e3b1e0bf4625e1c04a92fe..4e21c2c7d8ed08aeaf41c47b5569f0e747cc6c5c 100644
--- a/ash/common/shell_delegate.h
+++ b/ash/common/shell_delegate.h
@@ -133,9 +133,20 @@ class ASH_EXPORT ShellDelegate {
 
   virtual gfx::Image GetDeprecatedAcceleratorImage() const = 0;
 
-  // Toggles the status of the touchpad / touchscreen on or off.
+  // If |is_local| is true, returns the touchscreen status from local prefs,
+  // otherwise from user prefs.
+  virtual bool IsTouchscreenEnabledInPrefs(bool is_local) const = 0;

[Daniel Erat, 2016/12/02 21:48:56]

is_local feels a bit vague. would you mind renaming this to something like
use_local_state throughout?

[Qiang(Joe) Xu, 2016/12/02 23:55:10]

Done.

+
+  // Sets the status of touchscreen to |enabled| in prefs. If |is_local|, pref
+  // is set in local pref, otherwise in user pref.
+  virtual void SetTouchscreenEnabledInPrefs(bool enabled, bool is_local) = 0;
+
+  // Updates the on/off status of the touchscreen from the combination of local
+  // and user's preferences.
+  virtual void UpdateTouchscreenStatusFromPrefs() = 0;
+
+  // Toggles the status of the touchpad on or off.
   virtual void ToggleTouchpad() {}
-  virtual void ToggleTouchscreen() {}
 };
 
 }  // namespace ash