[CRX] Ignore auto-generated <embed> from Chrome

Fixes #11137

extensions/chromium/contentscript.js

@@ -62,6 +62,12 @@ function watchObjectOrEmbed(elem) {
     // Until #4483 is fixed, POST requests should be ignored.
     return;
   }
+  if (elem.tagName === 'EMBED' && elem.src === 'about:blank') {
+    // Starting from Chrome 76, internal embeds do not have the original URL,
+    // but "about:blank" instead.
+    // See https://github.com/mozilla/pdf.js/issues/11137
+    return;
+  }
 
   if (elem.__I_saw_this_element) {
     return;