Fix typos in createFrameWithWindowStopAbortedLoad

Set async=false on all three scripts instead of the first repeatedly.
The current typos are causing a test to be flaky (AdTaggingBrowserTest.
ChildrenOfFrameWithWindowStopAbortedLoad_StillCorrectlyTagged).

Bug: 1069346
Change-Id: Ib5c7f4994d25ebf4eedcc6d23ef2110c321bb454
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2148846
Commit-Queue: Alex Turner <alexmt@chromium.org>
Reviewed-by: John Delaney <johnidel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759076}

chrome/test/data/ad_tagging/create_frame.js

@@ -74,12 +74,12 @@ function createFrameWithWindowStopAbortedLoad(name) {
   frame.contentDocument.head.appendChild(script1);
 
   let script2 = document.createElement('script');
-  script1.async = false;
+  script2.async = false;
   script2.src = 'ad_script.js';
   frame.contentDocument.head.appendChild(script2);
 
   let script3 = document.createElement('script');
-  script1.async = false;
+  script3.async = false;
   script3.src = 'ad_script_2.js';
   // Set title so we know when all scripts have loaded.
   script3.onload = function() {