| <!DOCTYPE html> |
| <head> |
| <title>Performance Paint Timing: Check that paintTime/presentationTime are available</title> |
| </head> |
| <body> |
| <script src="resources/utils.js"></script> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script> |
| setup({"hide_test_state": true}); |
| promise_test(async t => { |
| assert_implements(window.PerformancePaintTiming, "Paint Timing isn't supported."); |
| assert_implements("paintTime" in window.PerformancePaintTiming.prototype, "Paint Timing doesn't expose `paintTime`"); |
| await new Promise(r => window.addEventListener('load', r)); |
| await assertNoFirstContentfulPaint(t); |
| const img = document.createElement('img'); |
| img.src = 'resources/circles.png'; |
| document.body.append(img); |
| const reference_time = performance.now(); |
| const performance_entry_promise = new Promise(resolve => { |
| new PerformanceObserver(entries => { |
| const [entry] = entries.getEntriesByName("first-contentful-paint"); |
| if (entry) |
| resolve(entry); |
| }).observe({type: "paint"}); |
| }); |
| const entry = await performance_entry_promise; |
| assert_greater_than(entry.paintTime, reference_time); |
| if ("presentationTime" in entry && entry.presentationTime !== null) { |
| assert_greater_than(entry.presentationTime, entry.paintTime); |
| assert_equals(entry.presentationTime, entry.startTime); |
| } else { |
| assert_equals(entry.paintTime, entry.startTime); |
| } |
| }, "Paint timing entries should expose paintTime and presentationTime"); |
| </script> |
| </body> |
| </html> |
