Deflake tests in http/tests/appcache/ when run in random order

third_party/WebKit/LayoutTests/http/tests/appcache/obsolete-error-events.html

Index: third_party/WebKit/LayoutTests/http/tests/appcache/obsolete-error-events.html
diff --git a/third_party/WebKit/LayoutTests/http/tests/appcache/obsolete-error-events.html b/third_party/WebKit/LayoutTests/http/tests/appcache/obsolete-error-events.html
index 62571d7a8cdf60b6735c1187eee781b752d3ac87..4f5f21c3ab9d3f574fe436ae10243d9dc1979342 100644
--- a/third_party/WebKit/LayoutTests/http/tests/appcache/obsolete-error-events.html
+++ b/third_party/WebKit/LayoutTests/http/tests/appcache/obsolete-error-events.html
@@ -4,11 +4,12 @@
 var jsTestIsAsync = true;
 description("Test that master list entries receive errors when manifest becomes obsolete.");
 
-function setManifestState(state)
+function setManifestState(state, callback)
 {
     var req = new XMLHttpRequest;
-    req.open("GET", "resources/fail-on-update.php?command=" + (state), false);
+    req.open("GET", "resources/fail-on-update.php?command=" + (state));
     req.send(null);
+    req.onload = callback;
 }
 
 var eventDetailsFromFrame = null;
@@ -43,15 +44,15 @@ function test()
     applicationCache.onnoupdate = function() { testFailed("Unexpected noupdate event") }
     applicationCache.oncached = function() { testFailed("Unexpected cached event") }
 
-    setManifestState('delete');
+    setManifestState('delete', () => {
+        // The frame will be associated to a cache, but update will obsolete it.
+        var ifr = document.createElement("iframe");
+        ifr.setAttribute("src", "resources/obsolete-error-events-frame.html");
+        document.body.appendChild(ifr);
 
-    // The frame will be associated to a cache, but update will obsolete it.
-    var ifr = document.createElement("iframe");
-    ifr.setAttribute("src", "resources/obsolete-error-events-frame.html");
-    document.body.appendChild(ifr);
-
-    applicationCache.onobsolete = onObsolete;
-    window.onmessage = onMessage;
+        applicationCache.onobsolete = onObsolete;
+        window.onmessage = onMessage;
+    });
 }
 
 function resetManifest()
@@ -61,11 +62,12 @@ function resetManifest()
         return;
     }
 
-    setManifestState('reset');
-    location.reload();
+    setManifestState('reset', () => {
+        location.reload();
+    });
 }
 
-applicationCache.oncached = function() {
+applicationCache.onnoupdate = applicationCache.oncached = function() {
     clearTimeout(timeoutId);
     test();
 };
@@ -73,6 +75,7 @@ applicationCache.oncached = function() {
 // If the manifest script happened to be in a wrong state, reset it.
 var timeoutId = setTimeout(resetManifest, 100);
 
+setTimeout(finishJSTest, 2000);
 </script>
 </body>
 </html>