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

media/capture/mojo/image_capture.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.
 
 module media.mojom;
 
 // Equivalent to idl MediaSettingsRange, arbitrary range representing the
 // allowed variations of a Capability or an Option.
 // https://w3c.github.io/mediacapture-image/#mediasettingsrange-section
 struct Range {
@@ skipping 11 matching lines @@
 
 //  https://www.w3.org/TR/image-capture/#FillLightMode
 enum FillLightMode { OFF, AUTO, FLASH };
 
 // Equivalent to idl's MediaTrackCapabilities plus PhotoCapabilities.
 struct PhotoCapabilities {
   // https://w3c.github.io/mediacapture-image/#mediatrackcapabilities-section
   MeteringMode white_balance_mode;
   MeteringMode exposure_mode;
   MeteringMode focus_mode;
+  array<Point2D> points_of_interest;
 
   Range exposure_compensation;
   Range color_temperature;
   Range iso;
 
   Range brightness;
   Range contrast;
   Range saturation;
   Range sharpness;
 
@@ skipping 80 matching lines @@
     // https://www.w3.org/TR/image-capture/#dom-imagecapture-setoptions
     SetOptions(string source_id, PhotoSettings settings)
         => (bool success);
 
     // Takes a Photo from the given |source_id|, returning it encoded in |blob|
     // with the format specified in its |mime_type|.
     // https://www.w3.org/TR/image-capture/#dom-imagecapture-takephoto
     TakePhoto(string source_id)
         => (Blob blob);
 };