Remove PROMISES_SUPPORTED check now that the promises code has landed.

BUG=358271
TEST=EME browser tests pass

Review URL: https://codereview.chromium.org/550933003

Cr-Commit-Position: refs/heads/master@{#293814}

media/test/data/eme_player_js/clearkey_player.js

@@ -23,11 +23,7 @@ ClearKeyPlayer.prototype.onMessage = function(message) {
       Utils.getInitDataFromMessage(message, this.testConfig.mediaType, true);
   var key = Utils.getDefaultKey(this.testConfig.forceInvalidResponse);
   var jwkSet = Utils.createJWKData(initData, key);
-  if (PROMISES_SUPPORTED) {
-    message.target.update(jwkSet).catch(function(error) {
-      Utils.failTest(error, KEY_ERROR);
-    });
-  } else {
-    message.target.update(jwkSet);
-  }
+  message.target.update(jwkSet).catch(function(error) {
+    Utils.failTest(error, KEY_ERROR);
+  });
 };

media/test/data/eme_player_js/globals.js

@@ -56,13 +56,10 @@ EME_VERSIONS_OPTIONS[EME_UNPREFIXED_VERSION] = EME_UNPREFIXED_VERSION;
 EME_VERSIONS_OPTIONS[EME_PREFIXED_VERSION] = EME_PREFIXED_VERSION;
 
 var EME_DISABLED_OPTIONS = [];
-var PROMISES_SUPPORTED = false;
 if (!document.createElement('video').webkitAddKey)
   EME_DISABLED_OPTIONS.push(EME_PREFIXED_VERSION);
 if (!document.createElement('video').setMediaKeys)
   EME_DISABLED_OPTIONS.push(EME_UNPREFIXED_VERSION);
-else
-  PROMISES_SUPPORTED = MediaKeys.create != undefined;
 
 // Global document elements ID's.
 var VIDEO_ELEMENT_ID = 'video';

media/test/data/eme_player_js/player_utils.js

@@ -59,14 +59,10 @@ PlayerUtils.registerEMEEventListeners = function(player) {
     try {
       var session = message.target.mediaKeys.createSession(
           message.contentType, message.initData);
-      if (PROMISES_SUPPORTED) {
-        session.then(addMediaKeySessionListeners)
-            .catch (function(error) {
-              Utils.failTest(error, KEY_ERROR);
-            });
-      } else {
-        addMediaKeySessionListeners(session);
-      }
+      session.then(addMediaKeySessionListeners)
+          .catch(function(error) {
+            Utils.failTest(error, KEY_ERROR);
+          });
     } catch (e) {
       Utils.failTest(e);
     }
@@ -74,15 +70,11 @@ PlayerUtils.registerEMEEventListeners = function(player) {
   this.registerDefaultEventListeners(player);
   try {
     Utils.timeLog('Setting video media keys: ' + player.testConfig.keySystem);
-    if (PROMISES_SUPPORTED) {
-      MediaKeys.create(player.testConfig.keySystem).then(function(mediaKeys) {
-        player.video.setMediaKeys(mediaKeys);
-      }).catch(function(error) {
-        Utils.failTest(error, NOTSUPPORTEDERROR);
-      });
-    } else {
-      player.video.setMediaKeys(new MediaKeys(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);
   }

media/test/data/eme_player_js/widevine_player.js

@@ -23,14 +23,9 @@ WidevinePlayer.prototype.onMessage = function(message) {
   function onSuccess(response) {
     var key = new Uint8Array(response);
     Utils.timeLog('Update media key session with license response.', key);
-    if (PROMISES_SUPPORTED) {
-      mediaKeySession.update(key).catch(function(error) {
-        Utils.failTest(error, KEY_ERROR);
-      });
-    } else {
-      mediaKeySession.update(key);
-    }
-
+    mediaKeySession.update(key).catch(function(error) {
+      Utils.failTest(error, KEY_ERROR);
+    });
   }
   Utils.sendRequest('POST',
                     'arraybuffer',