5 <script src="../../fast/repaint/resources/text-based-repaint.js"></script>
11 background-color: #a0a0a0;
21 background-color: #00a0a0;
22 -webkit-transform:translateZ(0);
27 if (window.internals) {
28 /* Note carefully, compositing for fixed position is _disabled_ here */
29 internals.settings.setPreferCompositingToLCDTextEnabled(false);
32 function repaintTest()
34 window.scrollTo(0, 100);
39 <body style="height:4000px;" onload="runRepaintTest()">
41 Among other duplicate bugs: https://code.google.com/p/chromium/issues/detail?id=151734
43 In the current code, a layer may actually be composited, but not have its own backing store.
44 In these cases, the layer paints into its composited ancestor with a backing store.
45 For fixed-position elements, however, this goes wrong because no other code
46 realizes that there is a software-painted fixed-position element. As a result,
47 the composited parent does not receive repaint invalidations, and the fixed-position
48 element incorrectly appears to be fixed to the composited element rather than the viewport.
50 The scenario that reproduces this: A fixed position element that has an overflow-clip with
51 a composited child. In this case, the fixed-position element needs to be composited.
52 However, this is one of the few reasons that does not require that the composited layer needs
53 its own backing store.
56 <!-- Scrolling should not cause either div to move around on the viewport. -->
57 <div class="fixedContainer">