feat(Ads): Add averageLoadTime and errors to ad stats (#6828)

externs/shaka/ads.js

@@ -12,9 +12,11 @@
 /**
  * @typedef {{
  *   loadTimes: !Array.<number>,
+ *   averageLoadTime: number,
  *   started: number,
  *   playedCompletely: number,
- *   skipped: number
+ *   skipped: number,
+ *   errors: number
  * }}
  *
  * @description
@@ -22,12 +24,16 @@
  *
  * @property {number} loadTimes
  *   The set of amounts of time it took to get the final manifest.
+ * @property {number} averageLoadTime
+ *   The average time it took to get the final manifest.
  * @property {number} started
  *   The number of ads started.
  * @property {number} playedCompletely
  *   The number of ads played completely.
  * @property {number} skipped
  *   The number of ads skipped.
+ * @property {number} errors
+ *   The number of ads with errors.
  * @exportDoc
  */
 shaka.extern.AdsStats;

lib/ads/ad_manager.js

@@ -852,6 +852,9 @@ shaka.ads.AdManager = class extends shaka.util.FakeEventTarget {
         case shaka.ads.AdManager.AD_SKIPPED:
           this.stats_.incrementSkipped();
           break;
+        case shaka.ads.AdManager.AD_ERROR:
+          this.stats_.incrementErrors();
+          break;
       }
     }
     this.dispatchEvent(event);

lib/ads/ads_stats.js

@@ -24,6 +24,8 @@ shaka.ads.AdsStats = class {
     this.playedCompletely_ = 0;
     /** @private {number} */
     this.skipped_ = 0;
+    /** @private {number} */
+    this.errors_ = 0;
   }
 
   /**
@@ -56,6 +58,26 @@ shaka.ads.AdsStats = class {
     this.skipped_++;
   }
 
+  /**
+   * Increase the number of ads with error by one.
+   */
+  incrementErrors() {
+    this.errors_++;
+  }
+
+  /**
+   * @return {number}
+   * @private
+   */
+  getAverageLoadTime_() {
+    if (!this.loadTimes_.length) {
+      return 0;
+    }
+    const sum = this.loadTimes_.reduce(
+        (accumulator, currentValue) => accumulator + currentValue, 0);
+    return sum / this.loadTimes_.length;
+  }
+
   /**
    * Create a stats blob that we can pass up to the app. This blob will not
    * reference any internal data.
@@ -65,9 +87,11 @@ shaka.ads.AdsStats = class {
   getBlob() {
     return {
       loadTimes: this.loadTimes_,
+      averageLoadTime: this.getAverageLoadTime_(),
       started: this.started_,
       playedCompletely: this.playedCompletely_,
       skipped: this.skipped_,
+      errors: this.errors_,
     };
   }
 };

ui/ad_statistics_button.js

@@ -98,9 +98,11 @@ shaka.ui.AdStatisticsButton = class extends shaka.ui.Element {
     /** @private {!Object.<string, function(string):string>} */
     this.parseFrom_ = {
       'loadTimes': parseLoadTimes,
+      'averageLoadTime': showNumber,
       'started': showNumber,
       'playedCompletely': showNumber,
       'skipped': showNumber,
+      'errors': showNumber,
     };
 
     /** @private {shaka.util.Timer} */

ui/ui.js

@@ -219,9 +219,11 @@ shaka.ui.Overlay = class {
       ],
       adStatisticsList: [
         'loadTimes',
+        'averageLoadTime',
         'started',
         'playedCompletely',
         'skipped',
+        'errors',
       ],
       contextMenuElements: [
         'loop',