Avoid cross-origin iframe issues when loading PDF in print preview

chrome/browser/resources/pdf/pdf_scripting_api.js

Index: chrome/browser/resources/pdf/pdf_scripting_api.js
diff --git a/chrome/browser/resources/pdf/pdf_scripting_api.js b/chrome/browser/resources/pdf/pdf_scripting_api.js
index 4a08195c83c5777d1b51c17883e9bde18ed3a017..63fd0480f6c91fb00137f24757b19f4b63074045 100644
--- a/chrome/browser/resources/pdf/pdf_scripting_api.js
+++ b/chrome/browser/resources/pdf/pdf_scripting_api.js
@@ -56,7 +56,8 @@ function PDFScriptingAPI(window, plugin) {
   this.setPlugin(plugin);
 
   window.addEventListener('message', function(event) {
-    if (event.origin != 'chrome-extension://mhjfbmdgcfjbbpaeojofohoefgiehjai') {
+    if (event.origin != 'chrome-extension://mhjfbmdgcfjbbpaeojofohoefgiehjai' &&
+        event.origin != 'chrome://print') {
       console.error('Received message that was not from the extension: ' +
                     event);
       return;
@@ -270,9 +271,7 @@ PDFScriptingAPI.prototype = {
  */
 function PDFCreateOutOfProcessPlugin(src) {
   var iframe = window.document.createElement('iframe');
-  iframe.setAttribute(
-      'src',
-      'chrome-extension://mhjfbmdgcfjbbpaeojofohoefgiehjai/index.html?' + src);
+  iframe.setAttribute('src', 'pdf_preview.html?' + src);
   // Prevent the frame from being tab-focusable.
   iframe.setAttribute('tabindex', '-1');
   var client = new PDFScriptingAPI(window);