fix: Evict buffer on QUOTA_EXCEEDED_ERROR error (#7361)

Evict buffer on QUOTA_EXCEEDED_ERROR error and also apply bufferingScale
to buffer behind config

lib/media/streaming_engine.js

@@ -82,7 +82,7 @@ shaka.media.StreamingEngine = class {
     this.deferredCloseSegmentIndex_ = new Map();
 
     /** @private {number} */
-    this.bufferingGoalScale_ = 1;
+    this.bufferingScale_ = 1;
 
     /** @private {?shaka.extern.Variant} */
     this.currentVariant_ = null;
@@ -1358,7 +1358,7 @@ shaka.media.StreamingEngine = class {
         this.config_.bufferingGoal);
 
     const scaledBufferingGoal = Math.max(1,
-        unscaledBufferingGoal * this.bufferingGoalScale_);
+        unscaledBufferingGoal * this.bufferingScale_);
 
     // Check if we've buffered to the end of the presentation.
     const timeUntilEnd =
@@ -1799,7 +1799,7 @@ shaka.media.StreamingEngine = class {
         }
         this.mediaStates_.delete(ContentType.TEXT);
       } else if (error.code == shaka.util.Error.Code.QUOTA_EXCEEDED_ERROR) {
-        this.handleQuotaExceeded_(mediaState, error);
+        await this.handleQuotaExceeded_(mediaState, error);
       } else {
         shaka.log.error(logPrefix, 'failed fetch and append: code=' +
             error.code);
@@ -1912,9 +1912,10 @@ shaka.media.StreamingEngine = class {
    *
    * @param {shaka.media.StreamingEngine.MediaState_} mediaState
    * @param {!shaka.util.Error} error
+   * @return {!Promise}
    * @private
    */
-  handleQuotaExceeded_(mediaState, error) {
+  async handleQuotaExceeded_(mediaState, error) {
     const logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
 
     // The segment cannot fit into the SourceBuffer. Ideally, MediaSource would
@@ -1943,11 +1944,11 @@ shaka.media.StreamingEngine = class {
       }
       // Reduction schedule: 80%, 60%, 40%, 20%, 16%, 12%, 8%, 4%, fail.
       // Note: percentages are used for comparisons to avoid rounding errors.
-      const percentBefore = Math.round(100 * this.bufferingGoalScale_);
+      const percentBefore = Math.round(100 * this.bufferingScale_);
       if (percentBefore > 20) {
-        this.bufferingGoalScale_ -= 0.2;
+        this.bufferingScale_ -= 0.2;
       } else if (percentBefore > 4) {
-        this.bufferingGoalScale_ -= 0.04;
+        this.bufferingScale_ -= 0.04;
       } else {
         shaka.log.error(
             logPrefix, 'MediaSource threw QuotaExceededError too many times');
@@ -1956,12 +1957,14 @@ shaka.media.StreamingEngine = class {
         this.playerInterface_.onError(error);
         return;
       }
-      const percentAfter = Math.round(100 * this.bufferingGoalScale_);
+      const percentAfter = Math.round(100 * this.bufferingScale_);
       shaka.log.warning(
           logPrefix,
           'MediaSource threw QuotaExceededError:',
           'reducing buffering goals by ' + (100 - percentAfter) + '%');
       mediaState.recovering = true;
+      const presentationTime = this.playerInterface_.getPresentationTime();
+      await this.evict_(mediaState, presentationTime);
     } else {
       shaka.log.debug(
           logPrefix,
@@ -2490,7 +2493,8 @@ shaka.media.StreamingEngine = class {
     // Use the max segment duration, if it is longer than the bufferBehind, to
     // avoid accidentally clearing too much data when dealing with a manifest
     // with a long keyframe interval.
-    const bufferBehind = Math.max(this.config_.bufferBehind,
+    const bufferBehind = Math.max(
+        this.config_.bufferBehind * this.bufferingScale_,
         this.manifest_.presentationTimeline.getMaxSegmentDuration());
 
     const startTime =