fix(WebOS): Do not preload DRM on legacy EME

lib/drm/drm_engine.js

@@ -550,6 +550,9 @@ shaka.drm.DrmEngine = class {
    * @return {!Promise}
    */
   async attach(video) {
+    if (this.video_ === video) {
+      return;
+    }
     if (!this.mediaKeys_) {
       // Unencrypted, or so we think.  We listen for encrypted events in order
       // to warn when the stream is encrypted, even though the manifest does

lib/media/preload_manager.js

@@ -23,6 +23,7 @@ goog.require('shaka.util.FakeEvent');
 goog.require('shaka.util.FakeEventTarget');
 goog.require('shaka.util.IDestroyable');
 goog.require('shaka.util.ObjectUtils');
+goog.require('shaka.util.Platform');
 goog.require('shaka.util.PlayerConfiguration');
 goog.require('shaka.util.PublicPromise');
 goog.require('shaka.util.Stats');
@@ -396,17 +397,21 @@ shaka.media.PreloadManager = class extends shaka.util.FakeEventTarget {
         await this.parseManifestInner_();
         this.throwIfDestroyed_();
 
-        await this.initializeDrmInner_();
-        this.throwIfDestroyed_();
+        if (!shaka.util.Platform.isMediaKeysPolyfilled('webkit')) {
+          await this.initializeDrm();
+          this.throwIfDestroyed_();
+        }
 
         await this.chooseInitialVariantAndPrefetchInner_();
         this.throwIfDestroyed_();
 
         // We don't need the drm keys to load completely for the initial variant
         // to be chosen, but we won't mark the load as a success until it has
         // been loaded. So wait for it here, not inside initializeDrmInner_.
-        await this.drmEngine_.waitForActiveRequests();
-        this.throwIfDestroyed_();
+        if (this.drmEngine_) {
+          await this.drmEngine_.waitForActiveRequests();
+          this.throwIfDestroyed_();
+        }
 
         this.successPromise_.resolve();
       } catch (error) {
@@ -559,13 +564,13 @@ shaka.media.PreloadManager = class extends shaka.util.FakeEventTarget {
 
   /**
    * Initializes the DRM engine.
-   *
+   * @param {?HTMLMediaElement=} media
    * @return {!Promise}
-   * @private
    */
-  async initializeDrmInner_() {
-    goog.asserts.assert(
-        this.manifest_, 'The manifest should already be parsed.');
+  async initializeDrm(media) {
+    if (!this.manifest_ || this.drmEngine_) {
+      return;
+    }
 
     this.makeStateChangeEvent_('drm-engine');
 
@@ -592,6 +597,10 @@ shaka.media.PreloadManager = class extends shaka.util.FakeEventTarget {
         playableVariants,
         this.manifest_.offlineSessionIds);
     this.throwIfDestroyed_();
+    if (media) {
+      await this.drmEngine_.attach(media);
+      this.throwIfDestroyed_();
+    }
 
     // Now that we have drm information, filter the manifest (again) so that
     // we can ensure we only use variants with the selected key system.

lib/player.js

@@ -1822,6 +1822,13 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
           this.configure('manifest.disableVideo', true);
         }
 
+        // Init DRM engine if it's not created yet (happens on polyfilled EME).
+        if (!preloadManager.getDrmEngine()) {
+          await mutexWrapOperation(async () => {
+            await preloadManager.initializeDrm(this.video_);
+          }, 'drmEngine_.init');
+        }
+
         // Get drm engine from preloader, then finalize it.
         this.drmEngine_ = preloadManager.receiveDrmEngine();
         await mutexWrapOperation(async () => {