Bug 1978352 [wpt PR 53866] - Fix timeout in mouse_wheel test, a=testonly

Automatic update from web-platform-tests
Fix timeout in mouse_wheel test

Problems with the test:
* potential to trigger input before the compositor is ready to handle
  the scroll
* scroll amount was insufficient. Though a mouse-wheel scroll is
  directional, test-driver.scroll emulates a touchpad, which is not
  directional. Due to the margin-bottom, the distance between snap
  points is 110 and the initial scroll of 50 would snap back to the
  starting position. This was the source of the Timeout.
* waitForAnimationEnd and waitForScrollTo resolve without an argument.
  Thus, the timestamp and evt were undefined.
* No benefit to waiting to reach a scroll position separate from
  waiting for the scroll position to stabilize, as the stabilization
  must trigger at a time well after the last scroll is received.
* A test that scrollend is received after the snap belongs in
  dom/event.
* Assert_equals is problematic for scroll position since the position
  can be tweaked to align with a physical pixel boundary to reduce
  anti-aliasing.

Bug: 40814982
Change-Id: I0ba377c7ca9c00d047ee020e1355625e2e1ccac4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6765747
Reviewed-by: David Awogbemila <awogbemilachromium.org>
Commit-Queue: Kevin Ellis <keverschromium.org>
Cr-Commit-Position: refs/heads/main{#1490359}

--

wpt-commits: 9633ad67f55f8c06cfdb0604258582d3f5c21ab8
wpt-pr: 53866

UltraBlame original commit: a4dba8bfbf3c06d3525cc5fde707a941a7ae2069

Author: marco-c

testing/web-platform/tests/css/css-scroll-snap/input/mouse-wheel.html

@@ -239,6 +239,27 @@
 src
 =
 "
+/
+dom
+/
+events
+/
+scrolling
+/
+scroll_support
+.
+js
+"
+>
+<
+/
+script
+>
+<
+script
+src
+=
+"
 .
 .
 /
@@ -275,6 +296,11 @@
 >
 <
 div
+id
+=
+"
+target
+"
 class
 =
 "
@@ -311,6 +337,11 @@
 =
 >
 {
+await
+waitForCompositorReady
+(
+)
+;
 const
 scroller
 =
@@ -378,6 +409,33 @@
 )
 ;
 const
+targetBounds
+=
+document
+.
+getElementById
+(
+'
+target
+'
+)
+.
+getBoundingClientRect
+(
+)
+;
+const
+dy
+=
+targetBounds
+.
+top
+/
+2
++
+1
+;
+const
 actions
 =
 new
@@ -392,7 +450,7 @@
 50
 50
 0
-50
+dy
 {
 origin
 :
@@ -416,12 +474,6 @@
 await
 scrollPromise
 ;
-let
-scrollEndTime
-;
-let
-snapEndTime
-;
 /
 /
 Detect
@@ -430,83 +482,69 @@
 in
 scrolling
 .
+As
+expected
+to
+snap
+right
+at
+the
+end
+of
+/
+/
+the
+scroll
+there
+should
+be
+no
+appreciable
+pause
+before
+the
+snap
+takes
+/
+/
+place
+.
+Once
+the
+scrolling
+settles
+we
+are
+expected
+to
+be
+at
+the
+snap
+/
+/
+position
+.
 const
 scrollStabilizedPromise
 =
 waitForAnimationEnd
 (
 scrollTop
 )
-.
-then
-(
-(
-timestamp
-)
-=
->
-{
-scrollEndTime
-=
-timestamp
-;
-}
-)
-;
-const
-snapEndPromise
-=
-waitForScrollTo
-(
-scroller
-(
-)
-=
->
-{
-return
-scroller
-.
-scrollTop
-;
-}
-110
-)
-.
-then
-(
-(
-evt
-)
-=
->
-{
-snapEndTime
-=
-evt
-.
-timestamp
-;
-}
-)
 ;
 await
-Promise
-.
-all
-(
-[
 scrollStabilizedPromise
-snapEndPromise
-]
-)
 ;
-assert_equals
+assert_approx_equals
 (
 scroller
 .
 scrollTop
 110
+0
+.
+5
 '
 Failed
 to
@@ -518,23 +556,6 @@
 '
 )
 ;
-assert_true
-(
-snapEndTime
-<
-scrollEndTime
-'
-Detected
-pause
-in
-scrolling
-before
-reaching
-snap
-target
-'
-)
-;
 }
 "
 Wheel
@@ -545,7 +566,9 @@
 to
 target
 position
-immediately
+without
+intermediate
+pause
 .
 "
 )