ShapeDetection: Update location of landmark to a sequence of points in WebIDL

These points describe a well-defined area along the detected landmark.
The modification of Spec has been merged with PR-40[1].

[1] https://github.com/WICG/shape-detection-api/pull/40

BUG=799319

Cq-Include-Trybots: luci.chromium.try:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win10_chromium_x64_rel_ng
Change-Id: If82ed74ab3c85afd7ac525b089b17839970e89c7
Reviewed-on: https://chromium-review.googlesource.com/997760Reviewed-by: Miguel Casas <mcasas@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Commit-Queue: Junwei Fu <junwei.fu@intel.com>
Cr-Commit-Position: refs/heads/master@{#550080}

third_party/WebKit/LayoutTests/shapedetection/detection-HTMLImageElement.html

@@ -37,7 +37,7 @@ function FaceDetectorDetectionResultTest(detectionResult, mock) {
   assert_equals(detectionResult.length, 3, "Number of faces");
   assert_equals(detectionResult[0].landmarks.length, 1, "Number of landmarks");
   assert_object_equals(detectionResult[0].landmarks[0],
-                      {type : 'eye', location : {x : 4.0, y : 5.0}},
+                      {type : 'eye', locations : [{x : 4.0, y : 5.0}]},
                       "landmark #1");
 }
 

third_party/blink/renderer/modules/shapedetection/face_detector.cc

@@ -74,8 +74,11 @@ void FaceDetector::OnDetectFaces(
       Point2D location;
       location.setX(landmark->location.x);
       location.setY(landmark->location.y);
+      HeapVector<Point2D> locations;
+      locations.push_back(location);
+
       Landmark web_landmark;
-      web_landmark.setLocation(location);
+      web_landmark.setLocations(locations);
       if (landmark->type == shape_detection::mojom::blink::LandmarkType::EYE) {
         web_landmark.setType("eye");
       } else if (landmark->type ==

third_party/blink/renderer/modules/shapedetection/landmark.idl

@@ -7,6 +7,6 @@ enum LandmarkType { "mouth", "eye" };
 
 // https://wicg.github.io/shape-detection-api/#dictdef-landmark
 dictionary Landmark {
-  required Point2D location;
+  required FrozenArray<Point2D> locations;
   LandmarkType type;
 };