Use composited scrolling if resizer needs to be above descendants
A resizer on an element containing composited stacked descendants
needs to be painted after the descendants. In pre-CompositeAfterPaint
this can only be achieved by using composited scrolling for the element
so that we'll composite the resizer even if the element is not
scrollable.
In CompositeAfterPaint everything is good because we always use the
correct paint order.
Bug: 1135676
Change-Id: Ic69b830ae3d71cd9f6b8f55deca591b485b189a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2523748
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825613}
diff --git a/css/css-ui/resize-child-will-change-transform-ref.html b/css/css-ui/resize-child-will-change-transform-ref.html
new file mode 100644
index 0000000..36f39fc
--- /dev/null
+++ b/css/css-ui/resize-child-will-change-transform-ref.html
@@ -0,0 +1,3 @@
+<!DOCTYPE html>
+<div style="width: 200px; height: 200px; overflow: hidden; resize: both; background: yellow">
+</div>
diff --git a/css/css-ui/resize-child-will-change-transform.html b/css/css-ui/resize-child-will-change-transform.html
new file mode 100644
index 0000000..b8adf53
--- /dev/null
+++ b/css/css-ui/resize-child-will-change-transform.html
@@ -0,0 +1,8 @@
+<!DOCTYPE html>
+<title>CSS resize: child with will-change: transform</title>
+<link rel="help" href="http://www.w3.org/TR/css3-ui/#resize">
+<link rel="author" title="Xianzhu Wang" href="mailto:wangxianzhu@chromium.org">
+<link rel="match" href="resize-child-will-change-transform-ref.html">
+<div id="resize" style="width: 200px; height: 200px; overflow: auto; resize: both">
+ <div id="will-change" style="width: 100%; height: 100%; background: yellow; will-change: transform"></div>
+</div>
