Revert of Fix Flaky EncryptedMediaTest (patchset #1 id:1 of...

Revert of Fix Flaky EncryptedMediaTest (patchset #1 id:1 of https://codereview.chromium.org/823743002/)

Reason for revert:
This changes introduces a new problem that is breaking the builds (e.g. http://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20MSan%20Browser%20%281%29/builds/3905).

Original issue's description:
> Fix Flaky EncryptedMediaTest
>
> Tests are flaky as setMediaKeys() was not completing before the
> "encrypted" event was generated. Change delays setting the video
> source until setMediaKeys() completes.
>
> BUG=444683
> TEST=Failing tests run fine locally
>
> Committed: https://crrev.com/37edfbac393c04549884ec15ce612a376a5be6ff
> Cr-Commit-Position: refs/heads/master@{#309568}

TBR=xhwang@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=444683

Review URL: https://codereview.chromium.org/826603002

Cr-Commit-Position: refs/heads/master@{#309587}

media/test/data/eme_player_js/player_utils.js

@@ -80,21 +80,19 @@ PlayerUtils.registerEMEEventListeners = function(player) {
   try {
     Utils.timeLog('Setting video media keys: ' + player.testConfig.keySystem);
     if (typeof navigator.requestMediaKeySystemAccess == 'function') {
-      return navigator.requestMediaKeySystemAccess(player.testConfig.keySystem)
+      navigator.requestMediaKeySystemAccess(player.testConfig.keySystem)
           .then(function(access) { return access.createMediaKeys(); })
           .then(function(mediaKeys) { player.video.setMediaKeys(mediaKeys); })
           .catch(function(error) { Utils.failTest(error, NOTSUPPORTEDERROR); });
     } else {
       // TODO(jrummell): Remove this once the blink change for
       // requestMediaKeySystemAccess lands.
-      return MediaKeys.create(player.testConfig.keySystem)
+      MediaKeys.create(player.testConfig.keySystem)
           .then(function(mediaKeys) { player.video.setMediaKeys(mediaKeys); })
           .catch(function(error) { Utils.failTest(error, NOTSUPPORTEDERROR); });
     }
   } catch (e) {
     Utils.failTest(e);
-    // Return a failing promise.
-    return new Promise(function(resolve, reject) { reject(Error(e)); });
   }
 };
 
@@ -151,9 +149,8 @@ PlayerUtils.setVideoSource = function(player) {
 };
 
 PlayerUtils.initEMEPlayer = function(player) {
-  var promise = this.registerEMEEventListeners(player);
-  promise.then(function(result) { PlayerUtils.setVideoSource(player); })
-      .catch(function(error) { Utils.failTest(error, NOTSUPPORTEDERROR); });
+  this.registerEMEEventListeners(player);
+  this.setVideoSource(player);
 };
 
 PlayerUtils.initPrefixedEMEPlayer = function(player) {