Bug 1051999 - Update pdf.js to version 1.0.645. r=yury

browser/extensions/pdfjs/README.mozilla

@@ -1,4 +1,4 @@
 This is the pdf.js project output, https://github.com/mozilla/pdf.js
 
-Current extension version is: 1.0.577
+Current extension version is: 1.0.645
 

browser/extensions/pdfjs/content/build/pdf.js

@@ -22,8 +22,8 @@ if (typeof PDFJS === 'undefined') {
   (typeof window !== 'undefined' ? window : this).PDFJS = {};
 }
 
-PDFJS.version = '1.0.577';
-PDFJS.build = '6865c28';
+PDFJS.version = '1.0.645';
+PDFJS.build = '66bfb9c';
 
 (function pdfjsWrapper() {
   // Use strict in our context only - users might not want it
@@ -465,15 +465,6 @@ function bytesToString(bytes) {
   return strBuf.join('');
 }
 
-function stringToArray(str) {
-  var length = str.length;
-  var array = [];
-  for (var i = 0; i < length; ++i) {
-    array[i] = str.charCodeAt(i);
-  }
-  return array;
-}
-
 function stringToBytes(str) {
   var length = str.length;
   var bytes = new Uint8Array(length);