| <!DOCTYPE html> |
| |
| <html> |
| <head> |
| <style> |
| body { |
| height: 1200px; |
| } |
| .box { |
| width: 100px; |
| height: 100px; |
| margin: 50px; |
| background-color: blue; |
| border: 2px solid black; |
| } |
| |
| #box { |
| background-image: linear-gradient(to top, white, black); |
| background-attachment: fixed; |
| background-repeat: no-repeat; |
| } |
| |
| #box.hidden { |
| display: none; |
| } |
| |
| #box.loaded { |
| background: transparent; |
| } |
| </style> |
| <script> |
| if (window.testRunner) |
| testRunner.dumpAsText(); |
| |
| function doTest() |
| { |
| var box = document.getElementById('box'); |
| box.classList.add('hidden'); |
| document.body.offsetWidth; |
| box.classList.remove('hidden'); |
| document.body.offsetWidth; |
| box.classList.add('loaded'); |
| |
| if (window.internals) |
| document.getElementById('reasons').textContent = window.internals.mainThreadScrollingReasons(); |
| } |
| window.addEventListener('load', doTest, false); |
| </script> |
| </head> |
| <body> |
| |
| <div id="box" class="box"></div> |
| <p>Test passes if there are no reasons for slow scrolling below.</p> |
| <pre id="reasons"></pre> |
| </body> |
| </html> |
