Overscan calibration UI.

ash/display/multi_display_manager.h

Index: ash/display/multi_display_manager.h
diff --git a/ash/display/multi_display_manager.h b/ash/display/multi_display_manager.h
index 0d2a4cf8134e888288ebe7230b7283e417c443aa..a7076b90ea14e00f7aa2f9775d34d2e42371d87b 100644
--- a/ash/display/multi_display_manager.h
+++ b/ash/display/multi_display_manager.h
@@ -78,6 +78,11 @@ class ASH_EXPORT MultiDisplayManager : public aura::DisplayManager,
   // display's bounds change.
   void SetOverscanInsets(int64 display_id, const gfx::Insets& insets_in_dip);
 
+  // Returns the current overscan insets for the specified |display_id|.
+  // Returns an empty insets (0, 0, 0, 0) if no insets are specified for
+  // the display.
+  gfx::Insets GetOverscanInsets(int64 display_id) const;
+
   // DisplayManager overrides:
   virtual void OnNativeDisplaysChanged(
       const std::vector<gfx::Display>& displays) OVERRIDE;