Issue 5028 - Use browser namespace

polyfill.js

+/*
+ * This file is part of Adblock Plus <https://adblockplus.org/>,
+ * Copyright (C) 2006-present eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+"use strict";
+
+(function()
+{
+  // On Edge, the extension APIs are in the "browser" namespace, whereas on
+  // both Firefox and Chrome they're in the "chrome" namespace. Firefox has a
+  // "browser" namespace too, but it is slightly incompatible in that the
+  // implementation uses promises as a fallback in the absence of a callback
+  // parameter. Edge sometimes has a "chrome" namespace, but with no extension
+  // APIs.
+  //
+  // In order to make the same code run on all three platforms, we simply look
+  // for a "chrome" namespace with the extension APIs and assign it to the
+  // "browser" namespace.
+  if (typeof chrome != "undefined" && "extension" in chrome)
+    window.browser = chrome;
+
+  // Workaround since HTMLCollection, NodeList, StyleSheet and
+  // CSSRuleList didn't have iterator support before Chrome 51.
+  // https://bugs.chromium.org/p/chromium/issues/detail?id=401699
+  let arrayIterator = Array.prototype[Symbol.iterator];
+  if (!(Symbol.iterator in HTMLCollection.prototype))
+    HTMLCollection.prototype[Symbol.iterator] = arrayIterator;
+  if (!(Symbol.iterator in NodeList.prototype))
+    NodeList.prototype[Symbol.iterator] = arrayIterator;
+  if (!(Symbol.iterator in StyleSheetList.prototype))
+    StyleSheetList.prototype[Symbol.iterator] = arrayIterator;
+  if (!(Symbol.iterator in CSSRuleList.prototype))
+    CSSRuleList.prototype[Symbol.iterator] = arrayIterator;
+}());