Split snaps-after-scrollbar-scrolling.html into two tests

Each of the 6 test cases in this test take a minimum of 200ms due to
the waitForAnimationEndTimeBased call. This was resulting in flakiness
due to being too close to the default timeout for web tests. Fix the
flakiness by separating them into two separate tests.

Leaving these tests disabled as there appears to be a different
underlying issues causing failures on Mac.

Bug: 1038354
Change-Id: I9fbf07f1e5a76e770bb1c028615fa36bbb6123fe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2477478
Commit-Queue: Mario Bianucci <mabian@microsoft.com>
Reviewed-by: Rahul Arakeri <arakeri@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#818715}

third_party/blink/web_tests/SlowTests

@@ -212,7 +212,8 @@ crbug.com/826957 fast/peerconnection/RTCPeerConnection-manyCandidates.html [ Slo
 crbug.com/853977 [ Linux ] http/tests/fetch/chromium/call-extra-crash-tee.html [ Slow ]
 crbug.com/853977 [ Linux ] http/tests/fetch/chromium/release-handle-crash.html [ Slow ]
 
-crbug.com/864887 [ Mac ] fast/scroll-snap/snaps-after-scrollbar-scrolling.html [ Slow ]
+crbug.com/864887 [ Mac ] fast/scroll-snap/snaps-after-scrollbar-scrolling-vertical.html [ Slow ]
+crbug.com/864887 [ Mac ] fast/scroll-snap/snaps-after-scrollbar-scrolling-horizontal.html [ Slow ]
 
 crbug.com/865262 [ Mac ] media/controls/text-track-menu-pointer-selection.html [ Slow ]
 

third_party/blink/web_tests/TestExpectations

@@ -5678,8 +5678,10 @@ crbug.com/1041830 http/tests/devtools/tracing/timeline-js/timeline-js-line-level
 # Enable scroll-snap tests on impl thread
 # These are currently failing on Mac which needs more investigation, snap-scrolls-visual-viewport seems flaky
 crbug.com/878878 [ Mac ] virtual/threaded/fast/scroll-snap/snaps-after-keyboard-scrolling.html [ Pass Timeout Failure ]
-crbug.com/878878 [ Mac ] virtual/threaded/fast/scroll-snap/snaps-after-scrollbar-scrolling.html [ Pass Timeout Failure ]
-crbug.com/878878 [ Win ] virtual/threaded/fast/scroll-snap/snaps-after-scrollbar-scrolling.html [ Pass Timeout Failure ]
+crbug.com/878878 [ Mac ] virtual/threaded/fast/scroll-snap/snaps-after-scrollbar-scrolling-vertical.html [ Pass Timeout Failure ]
+crbug.com/878878 [ Mac ] virtual/threaded/fast/scroll-snap/snaps-after-scrollbar-scrolling-horizontal.html [ Pass Timeout Failure ]
+crbug.com/878878 [ Win ] virtual/threaded/fast/scroll-snap/snaps-after-scrollbar-scrolling-vertical.html [ Pass Timeout Failure ]
+crbug.com/878878 [ Win ] virtual/threaded/fast/scroll-snap/snaps-after-scrollbar-scrolling-horizontal.html [ Pass Timeout Failure ]
 
 crbug.com/878878 virtual/threaded/fast/scroll-snap/animate-fling-to-snap-points.html [ Failure Pass Timeout ]
 crbug.com/878878 virtual/threaded/fast/scroll-snap/snap-scrolls-visual-viewport.html [ Failure Pass ]
@@ -5714,7 +5716,8 @@ crbug.com/1038091 virtual/gpu-rasterization/images/jpeg-yuv-image-decoding.html
 crbug.com/1038139 [ Win ] virtual/gpu-rasterization/images/2-comp.html [ Pass Failure ]
 
 # Sheriff 2019-12-30
-crbug.com/1038354 fast/scroll-snap/snaps-after-scrollbar-scrolling.html [ Pass Failure ]
+crbug.com/1038354 [ Mac ] fast/scroll-snap/snaps-after-scrollbar-scrolling-vertical.html [ Pass Failure ]
+crbug.com/1038354 [ Mac ] fast/scroll-snap/snaps-after-scrollbar-scrolling-horizontal.html [ Pass Failure ]
 
 # Sheriff 2020-01-02
 crbug.com/1038656 [ Mac ] http/tests/devtools/coverage/coverage-view-unused.js [ Pass Failure ]

third_party/blink/web_tests/fast/scroll-snap/snaps-after-scrollbar-scrolling.html → third_party/blink/web_tests/fast/scroll-snap/snaps-after-scrollbar-scrolling-horizontal.html

@@ -9,7 +9,6 @@
   <div id="space"></div>
   <div class="snap left top"></div>
   <div class="snap right top"></div>
-  <div class="snap left bottom"></div>
 </div>
 
 <script>
@@ -23,15 +22,6 @@ function scrollTop() {
   return scroller.scrollTop;
 }
 
-promise_test (async () => {
-  scroller.scrollTo(0, 0);
-  await mouseDragAndDrop(398, 20, 398, 120);
-  await waitForAnimationEndTimeBased(scrollTop);
-  await waitFor( () => {
-    return scroller.scrollTop == 400;
-  });
-}, "Snaps after dragging the vertical scrollbar.");
-
 promise_test (async () => {
   scroller.scrollTo(0, 0);
   await mouseDragAndDrop(20, 398, 120, 398);
@@ -41,15 +31,6 @@ promise_test (async () => {
   });
 }, "Snaps after dragging the horizontal scrollbar.");
 
-promise_test (async () => {
-  scroller.scrollTo(0, 0);
-  await mousePressOn(398, 350, 1000);
-  await waitForAnimationEndTimeBased(scrollTop);
-  await waitFor( () => {
-    return scroller.scrollTop == 400;
-  });
-}, "Snaps after clicking the vertical scrollbar.");
-
 promise_test (async () => {
   scroller.scrollTo(0, 0);
   await mousePressOn(350, 398, 1000);
@@ -59,15 +40,6 @@ promise_test (async () => {
   });
 }, "Snaps after clicking the horizontal scrollbar.");
 
-promise_test (async () => {
-  scroller.scrollTo(0, 0);
-  await touchTapOn(398, 350, 1000);
-  await waitForAnimationEndTimeBased(scrollTop);
-  await waitFor( () => {
-    return scroller.scrollTop == 400;
-  });
-}, "Snaps after tapping the vertical scrollbar.");
-
 promise_test (async () => {
   scroller.scrollTo(0, 0);
   await touchTapOn(350, 398, 1000);

third_party/blink/web_tests/fast/scroll-snap/snaps-after-scrollbar-scrolling-vertical.html

+<!DOCTYPE html>
+<link rel="help" href="https://drafts.csswg.org/css-scroll-snap-1" />
+<link rel="stylesheet" href="resources/simple-snap.css">
+<script src="../../resources/testharness.js"></script>
+<script src="../../resources/testharnessreport.js"></script>
+<script src="../../resources/gesture-util.js"></script>
+
+<div id='scroller'>
+  <div id="space"></div>
+  <div class="snap left top"></div>
+  <div class="snap left bottom"></div>
+</div>
+
+<script>
+var scroller = document.getElementById("scroller");
+
+function scrollLeft() {
+  return scroller.scrollLeft;
+}
+
+function scrollTop() {
+  return scroller.scrollTop;
+}
+
+promise_test (async () => {
+  scroller.scrollTo(0, 0);
+  await mouseDragAndDrop(398, 20, 398, 120);
+  await waitForAnimationEndTimeBased(scrollTop);
+  await waitFor( () => {
+    return scroller.scrollTop == 400;
+  });
+}, "Snaps after dragging the vertical scrollbar.");
+
+promise_test (async () => {
+  scroller.scrollTo(0, 0);
+  await mousePressOn(398, 350, 1000);
+  await waitForAnimationEndTimeBased(scrollTop);
+  await waitFor( () => {
+    return scroller.scrollTop == 400;
+  });
+}, "Snaps after clicking the vertical scrollbar.");
+
+promise_test (async () => {
+  scroller.scrollTo(0, 0);
+  await touchTapOn(398, 350, 1000);
+  await waitForAnimationEndTimeBased(scrollTop);
+  await waitFor( () => {
+    return scroller.scrollTop == 400;
+  });
+}, "Snaps after tapping the vertical scrollbar.");
+
+</script>