Fix test failures on IE 11 and Tizen

In these two environments, we must convert ES6 code to ES5.  Rather
than work around specific cases, we should let babel convert all test
code into ES5.

This fixes new problems on IE and Tizen introduced with the new demo,
and reverses some work-arounds that were used before.

Change-Id: I6be5ed2cd271e88bc7ebc1e878acbec6bbc21a2e

.eslintrc.js

@@ -140,6 +140,7 @@ module.exports = {
             },
             "files": [
                 // Closure requires using var in externs.
+                "ui/externs/*.js",
                 "externs/**/*.js",
                 "test/test/externs/*.js",
                 // Use var in load.js so it works in old browsers.  We'll use

demo/common/asset.js

@@ -344,40 +344,39 @@ const ShakaDemoAssetInfo = class {
   isStored() {
     return this.storedContent != null;
   }
-};
-
 
-/** @return {!ShakaDemoAssetInfo} */
-ShakaDemoAssetInfo.makeBlankAsset = function() {
-  return new ShakaDemoAssetInfo(
-    /* name= */ '',
-    /* iconUri= */ '',
-    /* manifestUri= */ '',
-    /* source= */ shakaAssets.Source.CUSTOM);
-};
+  /** @return {!ShakaDemoAssetInfo} */
+  static makeBlankAsset() {
+    return new ShakaDemoAssetInfo(
+      /* name= */ '',
+      /* iconUri= */ '',
+      /* manifestUri= */ '',
+      /* source= */ shakaAssets.Source.CUSTOM);
+  }
 
-/**
- * @param {!Object} raw
- * @return {!ShakaDemoAssetInfo}
- */
-ShakaDemoAssetInfo.fromJSON = function(raw) {
-  // This handles the special case for Maps in toJSON.
-  const parsed = {};
-  for (let key in raw) {
-    const value = raw[key];
-    if (value && typeof value == 'object' && value['__type__'] == 'map') {
-      const replacement = new Map();
-      for (let key in value) {
-        if (key != '__type__') {
-          replacement.set(key, value[key]);
+  /**
+   * @param {!Object} raw
+   * @return {!ShakaDemoAssetInfo}
+   */
+  static fromJSON(raw) {
+    // This handles the special case for Maps in toJSON.
+    const parsed = {};
+    for (let key in raw) {
+      const value = raw[key];
+      if (value && typeof value == 'object' && value['__type__'] == 'map') {
+        const replacement = new Map();
+        for (let key in value) {
+          if (key != '__type__') {
+            replacement.set(key, value[key]);
+          }
         }
+        parsed[key] = replacement;
+      } else {
+        parsed[key] = value;
       }
-      parsed[key] = replacement;
-    } else {
-      parsed[key] = value;
     }
+    const asset = ShakaDemoAssetInfo.makeBlankAsset();
+    Object.assign(asset, parsed);
+    return asset;
   }
-  const asset = ShakaDemoAssetInfo.makeBlankAsset();
-  Object.assign(asset, parsed);
-  return asset;
 };

demo/common/assets.js

@@ -23,13 +23,9 @@ goog.require('ShakaDemoAssetInfo');
 // Types and enums {{{
 /**
  * A container for demo assets.
- *
- * Note: due to an issue with testing on Tizen 2017, we must use "var" at this
- * scope instead of "let".
- *
  * @class
  */
-var shakaAssets = {};  // eslint-disable-line no-var
+const shakaAssets = {};
 
 
 /** @enum {string} */

karma.conf.js

@@ -131,7 +131,8 @@ module.exports = function(config) {
       // Compute coverage over UI, too
       'ui/*.js': ['coverage'],
 
-      // Convert ES6 to ES5 so we can still run tests on IE11.
+      // Convert ES6 to ES5 so we can still run tests on IE11 and Tizen.
+      'demo/common/*.js': ['babel'],
       'lib/**/*.js': ['babel'],
       'ui/**/*.js': ['babel'],
       'test/**/*.js': ['babel'],

ui/externs/ui.js

@@ -23,7 +23,7 @@
  */
 
 /** @namespace */
-var shaka = {}; // eslint-disable-line no-var
+var shaka = {};
 
 /** @namespace */
 shaka.extern = {};