Add overscanCalibration methods to system_display.idl

extensions/common/api/system_display.idl

 // Copyright 2013 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.
 
 // Use the <code>system.display</code> API to query display metadata.
 namespace system.display {
 
   dictionary Bounds {
     // The x-coordinate of the upper-left corner.
     long left;
@@ skipping 162 matching lines @@
         DOMString id,
         DisplayProperties info,
         optional SetDisplayUnitInfoCallback callback);
 
     // Enables/disables the unified desktop feature. Note that this simply
     // enables the feature, but will not change the actual desktop mode.
     // (That is, if the desktop is in mirror mode, it will stay in mirror mode)
     // NOTE: This is only available to Chrome OS Kiosk apps and Web UI.
     // |enabled|: True if unified desktop should be enabled.
     static void enableUnifiedDesktop(boolean enabled);
+
+    // Starts overscan calibration for a display. This will show an overlay
+    // on the screen indicating the current overscan insets. If overscan
+    // calibration for display |id| is in progress this will reset calibration.
+    // |id|: The display's unique identifier.
+    static void overscanCalibrationStart(DOMString id);
+
+    // Adjusts the current overscan insets for a display. Typically this should
+    // etiher move the display along an axis (e.g. left+right have the same
+    // value) or scale it along an axis (e.g. top+bottom have opposite values).
+    // Each Adjust call is cumulative with previous calls since Start.
+    // |id|: The display's unique identifier.
+    // |delta|: The amount to change the overscan insets.
+    static void overscanCalibrationAdjust(DOMString id, Insets delta);
+
+    // Resets the overscan insets for a display to the last saved value (i.e
+    // before Start was called).
+    // |id|: The display's unique identifier.
+    static void overscanCalibrationReset(DOMString id);
+
+    // Complete overscan adjustments for a display  by saving the current values

[oshima, 2016/05/21 01:16:36]

nit: extra space between "display" and "by"

+    // and hiding the overlay.
+    // |id|: The display's unique identifier.
+    static void overscanCalibrationComplete(DOMString id);
   };
 
   interface Events {
     // Fired when anything changes to the display configuration.
     static void onDisplayChanged();
   };
 };