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..d95f49acfeaf28ef1d65b3db5558ec4f3f24b363 100644
--- a/ash/common/shell_delegate.h
+++ b/ash/common/shell_delegate.h
@@ -133,9 +133,21 @@ class ASH_EXPORT ShellDelegate {
 
   virtual gfx::Image GetDeprecatedAcceleratorImage() const = 0;
 
-  // Toggles the status of the touchpad / touchscreen on or off.
+  // If |use_local_state| is true, returns the touchscreen status from local
+  // state, otherwise from user prefs.
+  virtual bool IsTouchscreenEnabledInPrefs(bool use_local_state) const = 0;
+
+  // Sets the status of touchscreen to |enabled| in prefs. If |use_local_state|,
+  // pref is set in local state, otherwise in user prefs.
+  virtual void SetTouchscreenEnabledInPrefs(bool enabled,
+                                            bool use_local_state) = 0;
+
+  // Updates the enabled/disabled status of the touchscreen from prefs. Enabled
+  // if both local state and user prefs are enabled, otherwise disabled.
+  virtual void UpdateTouchscreenStatusFromPrefs() = 0;
+
+  // Toggles the status of touchpad between enabled and disabled.
   virtual void ToggleTouchpad() {}
-  virtual void ToggleTouchscreen() {}
 };
 
 }  // namespace ash