Shape Detection: add SaveSameObject idl to SameObject annotations

third_party/WebKit/Source/modules/shapedetection/DetectedBarcode.idl

 // Copyright 2016 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.
 
 // https://wicg.github.io/shape-detection-api/#barcode-detection-api
 
 [
     Constructor,
     RuntimeEnabled=ShapeDetection,
 ] interface DetectedBarcode {
     // TODO(mcasas): Implement missing fields. https://crbug.com/646083
-    [SameObject] readonly attribute DOMString rawValue;
-    [SameObject] readonly attribute DOMRect boundingBox;
+    [SameObject, SaveSameObject] readonly attribute DOMString rawValue;

[Yuki, 2017/05/10 06:37:37]

Please double-check on your side, but IIUC, we don't need [SaveSameObject] here
because DOMString is not an Object, you cannot distinguish two strings with the
same content (if the content is the same, then two strings are identical).

+    [SameObject, SaveSameObject] readonly attribute DOMRect boundingBox;

[Yuki, 2017/05/10 06:37:37]

Please double-check on your side, but we shouldn't need [SaveSameObject] here,
too, as long as you're returning the same blink::DOMRect* from
DetectedBarcode::boundingBox().

We apologize this confusing situation, but you only need [SaveSameObject] for
|cornerPoints| that returns a FrozenArray, because corner_points_ of type
HeapVector<Point2D> is not a ScriptWrappable and we cannot associate a wrapper
to it.

[mcasas, 2017/05/10 19:00:45]

OIC! Apologies for the misunderstanding; next Ps will
only keep [SaveSameObject] for the FrozenArray<>s.

     // 4 corner points in clockwise direction starting with top-left. Due to
     // possible perspective distortions, this is not necessarily a rectangle.
-    [SameObject] readonly attribute FrozenArray<Point2D> cornerPoints;
+    [SameObject, SaveSameObject] readonly attribute FrozenArray<Point2D> cornerPoints;
 };