lazy-load: Increase timeout value to reduce flakes

The test is still a bit flaky after increasing the value to 400ms (
which did in fact reduce flakiness substantially). This CL will
increase the value even further (600ms) to further reduce the flakiness.

TBR=iclelland@chromium.org

Bug: 915236
Change-Id: I1ad650ed14dbf9b054a966324ec033a4bd2f47f8
Reviewed-on: https://chromium-review.googlesource.com/c/1379105
Reviewed-by: Ehsan Karamad <ekaramad@chromium.org>
Commit-Queue: Ehsan Karamad <ekaramad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#616867}
diff --git a/feature-policy/experimental-features/lazyload/lazyload-disabled-tentative.sub.html b/feature-policy/experimental-features/lazyload/lazyload-disabled-tentative.sub.html
index 5b9034b..772998a 100644
--- a/feature-policy/experimental-features/lazyload/lazyload-disabled-tentative.sub.html
+++ b/feature-policy/experimental-features/lazyload/lazyload-disabled-tentative.sub.html
@@ -25,7 +25,7 @@
       "http://{{hosts[alt][www]}}:{{ports[http][0]}}/" +
       "feature-policy/experimental-features/resources/lazyload-contents.html";
 
-  let load_timeout = 400; // ms
+  let load_timeout = 600; // ms
   let expected_timeout_msg = false;
 
   window.scrollTo(0, 0);
diff --git a/feature-policy/experimental-features/lazyload/lazyload-enabled-tentative.sub.html b/feature-policy/experimental-features/lazyload/lazyload-enabled-tentative.sub.html
index 2e0a791..058b025 100644
--- a/feature-policy/experimental-features/lazyload/lazyload-enabled-tentative.sub.html
+++ b/feature-policy/experimental-features/lazyload/lazyload-enabled-tentative.sub.html
@@ -25,7 +25,7 @@
       "http://{{hosts[alt][www]}}:{{ports[http][0]}}/" +
       "feature-policy/experimental-features/resources/lazyload-contents.html";
 
-  let load_timeout = 400; // ms
+  let load_timeout = 600; // ms
   let expected_timeout_msg = false;
   let expected_load_msg = "This page is lazyloaded.";