Image Capture: add |points_of_interest| to mojo and wire it to IDL layer

third_party/WebKit/LayoutTests/imagecapture/resources/mock-imagecapture.js

 "use strict";
 
 let mockImageCaptureReady = define(
   'mockImageCapture',
   ['media/capture/mojo/image_capture.mojom',
    'mojo/public/js/bindings',
    'content/public/renderer/interfaces',
   ], (imageCapture, bindings, interfaces) => {
 
   class MockImageCapture {
@@ skipping 15 matching lines @@
           fill_light_mode : [ imageCapture.FillLightMode.AUTO,
                               imageCapture.FillLightMode.FLASH],
           red_eye_reduction : imageCapture.RedEyeReduction.CONTROLLABLE,
           torch : false,
           color_temperature :
               { min : 2500.0, max : 6500.0, current : 6000.0, step : 1000.0 },
           brightness : { min : 1.0, max : 10.0, current : 5.0, step : 1.0 },
           contrast : { min : 2.0, max : 9.0, current : 5.0, step : 1.0 },
           saturation : { min : 3.0, max : 8.0, current : 6.0, step : 1.0 },
           sharpness : { min : 4.0, max : 7.0, current : 7.0, step : 1.0 },
-          points_of_interest : [],
+          points_of_interest : [{x : 0.4, y : 0.6}],
       }};
       this.settings_ = null;
       this.bindingSet_ = new bindings.BindingSet(imageCapture.ImageCapture);
     }
 
     getCapabilities(source_id) {
       return Promise.resolve(this.state_);
     }
 
     setOptions(source_id, settings) {
@@ skipping 57 matching lines @@
       return this.state_.capabilities;
     }
 
     options() {
       return this.settings_;
     }
 
   }
   return new MockImageCapture();
 });