[CCA] Treat 848:480 as 16:9 aspect ratio

Bug: b:147986763
Test: Pass 'tast run <DUT> camera.CCAUIResolutions' with
crrev.com/c/2128208 on treeya

Change-Id: Ia3181cbfd0438b36f403ace4f4771b0fdfd40955
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2127995Reviewed-by: Wei Lee <wtlee@chromium.org>
Reviewed-by: Shik Chen <shik@chromium.org>
Commit-Queue: Kuo Jen Wei <inker@chromium.org>
Auto-Submit: Kuo Jen Wei <inker@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756956}

chrome/browser/resources/chromeos/camera/src/js/device/constraints_preferrer.js

@@ -501,17 +501,26 @@ export class PhotoConstraintsPreferrer extends ConstraintsPreferrer {
    * @private
    */
   pairCapturePreviewResolutions_(captureResolutions, previewResolutions) {
+    const toSupportedPreviewRatio = (r) => {
+      // Special aspect ratio mapping rule, see http://b/147986763.
+      if (r.width === 848 && r.height === 480) {
+        return (new Resolution(16, 9)).aspectRatio;
+      }
+      return r.aspectRatio;
+    };
     /** @type {!Object<string, !ResolutionList>} */
     const previewRatios = previewResolutions.reduce((rs, r) => {
-      rs[r.aspectRatio] = rs[r.aspectRatio] || [];
-      rs[r.aspectRatio].push(r);
+      const ratio = toSupportedPreviewRatio(r);
+      rs[ratio] = rs[ratio] || [];
+      rs[ratio].push(r);
       return rs;
     }, {});
     /** @type {!Object<string, !ResolutionList>} */
     const captureRatios = captureResolutions.reduce((rs, r) => {
-      if (r.aspectRatio in previewRatios) {
-        rs[r.aspectRatio] = rs[r.aspectRatio] || [];
-        rs[r.aspectRatio].push(r);
+      const ratio = toSupportedPreviewRatio(r);
+      if (ratio in previewRatios) {
+        rs[ratio] = rs[ratio] || [];
+        rs[ratio].push(r);
       }
       return rs;
     }, {});