ShapeDetection: implement barcode detection, blink part

third_party/WebKit/public/platform/modules/shapedetection/shapedetection.mojom

 // 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/#api
 
 module blink.mojom;
 
 import "ui/gfx/geometry/mojo/geometry.mojom";
 
-// Because "//ui/gfx/geometry/mojo" is not exposed to blink, we need to declare
+// Since "//ui/gfx/geometry/mojo" is not exposed to blink, we need to declare
 // a wrapper struct, so that gfx.mojom.RectF will not be directly referenced
-// inside blink, and browser can still use gfx types.
+// inside Blink, and browser can still use gfx types.
 struct FaceDetectionResult {
   array<gfx.mojom.RectF> boundingBoxes;
 };
 
+struct BarcodeDetectionResult {
+  string raw_value;

[Tom Sepez, 2016/11/15 18:31:00]

What values can this string take?  Can we use an enum instead?

[mcasas, 2016/11/15 19:05:25]

This is the string encoded in a QR/barcode and
can take many forms, e.g. it can be a phone
number "tel:+1-212-555-1212", or a URL
"MEBKM:TITLE:Google;URL:https://www.google.com;;",
whose semantics are delegated to the WebApp.
Added explanation.

+  gfx.mojom.RectF bounding_box;
+};
+
 interface ShapeDetection {
-  // frame_data contains tightly packed image pixels in ARGB32 format,
+  // |frame_data| contains tightly packed image pixels in ARGB32 format,
   // row-major order.
-  DetectFace(handle<shared_buffer> frame_data, uint32 width, uint32 height)
+  DetectFaces(handle<shared_buffer> frame_data, uint32 width, uint32 height)
     => (FaceDetectionResult result);
+
+  DetectBarcodes(handle<shared_buffer> frame_data, uint32 width, uint32 height)

[dcheng, 2016/11/15 01:47:38]

I think rsesek@ has mentioned this elsewhere, but let's use an actual type to
represent bitmaps (in this case, SkBitmap from
https://cs.chromium.org/chromium/src/skia/public/interfaces/bitmap.mojom?rcl=...
should work nicely).

[mcasas, 2016/11/15 19:05:25]

Added a TODO+bug to address this suggestion, thanks!

+    => (array<BarcodeDetectionResult> results);
 };