Uses document.currentScript for pdf.worker.js path.

src/pdf.js

@@ -42,10 +42,8 @@ if (!PDFJS.workerSrc && typeof document !== 'undefined') {
   // workerSrc is not set -- using last script url to define default location
   PDFJS.workerSrc = (function () {
     'use strict';
-    var scriptTagContainer = document.body ||
+    var pdfJsSrc = document.currentScript.src;
-                             document.getElementsByTagName('head')[0];
+    return pdfJsSrc && pdfJsSrc.replace(/\.js$/i, '.worker.js');
-    var pdfjsSrc = scriptTagContainer.lastChild.src;
-    return pdfjsSrc && pdfjsSrc.replace(/\.js$/i, '.worker.js');
   })();
 }
 //#endif

web/compatibility.js

@@ -577,3 +577,19 @@ if (typeof PDFJS === 'undefined') {
     PDFJS.disableFullscreen = true;
   }
 })();
+
+// Provides document.currentScript support
+// Support: IE, Chrome<29.
+(function checkCurrentScript() {
+  if ('currentScript' in document) {
+    return;
+  }
+  Object.defineProperty(document, 'currentScript', {
+    get: function () {
+      var scripts = document.getElementsByTagName('script');
+      return scripts[scripts.length - 1];
+    },
+    enumerable: true,
+    configurable: true
+  });
+})();