| <!doctype html> |
| <script src="../resources/testharness.js"></script> |
| <script src="../resources/testharnessreport.js"></script> |
| |
| <div id="box" style="width: 100px; height: 100px; background: blue;"></div> |
| |
| <script> |
| var t = async_test('Integration test for background style change updates'); |
| |
| t.step(function() { |
| assert_true(!!window.internals, 'Test requires window.internals'); |
| }); |
| |
| // Loading is non-deterministic so record the initial count after onload |
| // plus a paint. |
| onload = function() { |
| requestAnimationFrame(function() { |
| // Windows flakily sends mouse events on the first frame so wait an |
| // additional frame before starting the test. |
| requestAnimationFrame(function() { |
| var initialLifecycleCount = internals.LifecycleUpdateCount(); |
| |
| box.style.background = 'green'; |
| |
| requestAnimationFrame(function() { |
| var postChangeCount = internals.LifecycleUpdateCount(); |
| t.step(function() { |
| // A background style change should have only resulted in a single |
| // lifecycle update. If this ever fails, something is causing an |
| // unnecessary lifecycle update. |
| assert_equals(postChangeCount, initialLifecycleCount + 1, |
| 'a style change should cause one lifecycle update'); |
| }); |
| |
| // A timeout is used so we can capture unnecessary updates. 250ms was |
| // chosen because it is the lowest value that would reliably fail for |
| // https://crbug.com/866981 and https://crbug.com/868983 on bots; lower |
| // values would just become flaky. |
| setTimeout(function() { |
| t.step(function() { |
| // The timeout should cause a single additional update. If this ever |
| // fails, something is causing an unnecessary lifecycle update. |
| assert_equals(internals.LifecycleUpdateCount(), postChangeCount + 1, |
| 'a timeout should cause one lifecycle update'); |
| }); |
| t.done(); |
| }, 250); |
| }); |
| }); |
| }); |
| } |
| </script> |
