Backed out 3 changesets (bug 1827975, bug 1831580) for causing mochitests failures in test_group_scrollend.html.

Backed out changeset 760e07b3a5ae (bug 1831580)
Backed out changeset 87f29c301be9 (bug 1827975)
Backed out changeset 8d034bde14e5 (bug 1827975)

gfx/layers/apz/src/AsyncPanZoomController.cpp

@@ -2109,12 +2109,6 @@ nsEventStatus AsyncPanZoomController::OnKeyboard(const KeyboardInput& aEvent) {
   // exists
   if (mState != KEYBOARD_SCROLL) {
     CancelAnimation();
-    // Keyboard input that does not change the scroll position should not
-    // cause a TransformBegin state change, in order to avoid firing a
-    // scrollend event when no scrolling occurred.
-    if (ConvertDestinationToDelta(destination) == ParentLayerPoint()) {
-      return nsEventStatus_eConsumeDoDefault;
-    }
     SetState(KEYBOARD_SCROLL);
 
     nsPoint initialPosition =
@@ -3945,20 +3939,6 @@ void AsyncPanZoomController::HandleSmoothScrollOverscroll(
                         BuildOverscrollHandoffChain(), nullptr);
 }
 
-ParentLayerPoint AsyncPanZoomController::ConvertDestinationToDelta(
-    CSSPoint& aDestination) const {
-  ParentLayerPoint startPoint, endPoint;
-
-  {
-    RecursiveMutexAutoLock lock(mRecursiveMutex);
-
-    startPoint = aDestination * Metrics().GetZoom();
-    endPoint = Metrics().GetVisualScrollOffset() * Metrics().GetZoom();
-  }
-
-  return endPoint - startPoint;
-}
-
 void AsyncPanZoomController::SmoothScrollTo(
     CSSSnapDestination&& aDestination,
     ScrollTriggeredByScript aTriggeredByScript, const ScrollOrigin& aOrigin) {
@@ -3985,13 +3965,6 @@ void AsyncPanZoomController::SmoothScrollTo(
   }
 
   CancelAnimation();
-
-  // If no scroll is required, we should exit early to avoid triggering
-  // a scrollend event when no scrolling occurred.
-  if (ConvertDestinationToDelta(aDestination.mPosition) == ParentLayerPoint()) {
-    return;
-  }
-
   SetState(SMOOTH_SCROLL);
   nsPoint initialPosition =
       CSSPoint::ToAppUnits(Metrics().GetVisualScrollOffset());
@@ -4013,30 +3986,24 @@ void AsyncPanZoomController::SmoothMsdScrollTo(
     animation->SetDestination(aDestination.mPosition,
                               std::move(aDestination.mTargetIds),
                               aTriggeredByScript);
-    return;
-  }
+  } else {
+    CancelAnimation();
+    SetState(SMOOTHMSD_SCROLL);
+    // Convert velocity from ParentLayerPoints/ms to ParentLayerPoints/s.
+    CSSPoint initialVelocity;
+    if (Metrics().GetZoom() != CSSToParentLayerScale(0)) {
+      initialVelocity = ParentLayerPoint(mX.GetVelocity() * 1000.0f,
+                                         mY.GetVelocity() * 1000.0f) /
+                        Metrics().GetZoom();
+    }
 
-  // If no scroll is required, we should exit early to avoid triggering
-  // a scrollend event when no scrolling occurred.
-  if (ConvertDestinationToDelta(aDestination.mPosition) == ParentLayerPoint()) {
-    return;
+    StartAnimation(new SmoothMsdScrollAnimation(
+        *this, Metrics().GetVisualScrollOffset(), initialVelocity,
+        aDestination.mPosition,
+        StaticPrefs::layout_css_scroll_behavior_spring_constant(),
+        StaticPrefs::layout_css_scroll_behavior_damping_ratio(),
+        std::move(aDestination.mTargetIds), aTriggeredByScript));
   }
-  CancelAnimation();
-  SetState(SMOOTHMSD_SCROLL);
-  // Convert velocity from ParentLayerPoints/ms to ParentLayerPoints/s.
-  CSSPoint initialVelocity;
-  if (Metrics().GetZoom() != CSSToParentLayerScale(0)) {
-    initialVelocity = ParentLayerPoint(mX.GetVelocity() * 1000.0f,
-                                       mY.GetVelocity() * 1000.0f) /
-                      Metrics().GetZoom();
-  }
-
-  StartAnimation(new SmoothMsdScrollAnimation(
-      *this, Metrics().GetVisualScrollOffset(), initialVelocity,
-      aDestination.mPosition,
-      StaticPrefs::layout_css_scroll_behavior_spring_constant(),
-      StaticPrefs::layout_css_scroll_behavior_damping_ratio(),
-      std::move(aDestination.mTargetIds), aTriggeredByScript));
 }
 
 void AsyncPanZoomController::StartOverscrollAnimation(
@@ -5520,7 +5487,6 @@ void AsyncPanZoomController::NotifyLayersUpdated(
         aScrollMetadata.GetOverscrollBehavior());
   }
 
-  bool instantScrollMayTriggerTransform = false;
   bool scrollOffsetUpdated = false;
   bool smoothScrollRequested = false;
   bool didCancelAnimation = false;
@@ -5598,11 +5564,6 @@ void AsyncPanZoomController::NotifyLayersUpdated(
     MOZ_ASSERT(scrollUpdate.GetMode() == ScrollMode::Instant ||
                scrollUpdate.GetMode() == ScrollMode::Normal);
 
-    instantScrollMayTriggerTransform =
-        scrollUpdate.GetMode() == ScrollMode::Instant &&
-        scrollUpdate.GetScrollTriggeredByScript() ==
-            ScrollTriggeredByScript::No;
-
     // If the layout update is of a higher priority than the visual update, then
     // we don't want to apply the visual update.
     // If the layout update is of a clobbering type (or a smooth scroll request,
@@ -5735,15 +5696,6 @@ void AsyncPanZoomController::NotifyLayersUpdated(
     // Since the main-thread scroll offset changed we should trigger a
     // recomposite to make sure it becomes user-visible.
     ScheduleComposite();
-
-    // If the scroll offset was updated, we're not in a transforming state,
-    // and we are scrolling by a non-zero delta, we should ensure
-    // TransformBegin and TransformEnd notifications are sent.
-    if (!IsTransformingState(mState) && instantScrollMayTriggerTransform &&
-        cumulativeRelativeDelta && *cumulativeRelativeDelta != CSSPoint() &&
-        !didCancelAnimation) {
-      SendTransformBeginAndEnd();
-    }
   } else if (needToReclampScroll) {
     // Even if we didn't accept a new scroll offset from content, the
     // scrollable rect or composition bounds may have changed in a way that
@@ -6275,14 +6227,6 @@ void AsyncPanZoomController::DispatchStateChangeNotification(
     }
   }
 }
-void AsyncPanZoomController::SendTransformBeginAndEnd() {
-  RefPtr<GeckoContentController> controller = GetGeckoContentController();
-  if (controller) {
-    controller->NotifyAPZStateChange(GetGuid(),
-                                     APZStateChange::eTransformBegin);
-    controller->NotifyAPZStateChange(GetGuid(), APZStateChange::eTransformEnd);
-  }
-}
 
 bool AsyncPanZoomController::IsInTransformingState() const {
   RecursiveMutexAutoLock lock(mRecursiveMutex);

gfx/layers/apz/src/AsyncPanZoomController.h

@@ -1477,13 +1477,6 @@ class AsyncPanZoomController {
    */
   void DispatchStateChangeNotification(PanZoomState aOldState,
                                        PanZoomState aNewState);
-
-  /**
-   * Send a TransformBegin notification followed by a TransformEnd
-   * notification.
-   */
-  void SendTransformBeginAndEnd();
-
   /**
    * Internal helpers for checking general state of this apzc.
    */
@@ -1611,8 +1604,6 @@ class AsyncPanZoomController {
                       ScrollTriggeredByScript aTriggeredByScript,
                       const ScrollOrigin& aOrigin);
 
-  ParentLayerPoint ConvertDestinationToDelta(CSSPoint& aDestination) const;
-
   // Start a smooth-scrolling animation to the given destination, with MSD
   // physics that is suited for scroll-snapping.
   void SmoothMsdScrollTo(CSSSnapDestination&& aDestination,

gfx/layers/apz/test/mochitest/helper_keyboard_scrollend.html

@@ -1,121 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-  <meta charset="utf-8">
-  <meta name="viewport" content="initial-scale=1,width=device-width">
-  <script src="apz_test_utils.js"></script>
-  <script src="apz_test_native_event_utils.js"></script>
-  <script src="/tests/SimpleTest/EventUtils.js"></script>
-  <script src="/tests/SimpleTest/NativeKeyCodes.js"></script>
-  <script src="/tests/SimpleTest/paint_listener.js"></script>
-  <style>
-#scroller {
-  height: 50vh;
-  width: 50vw;
-  overflow: scroll;
-  overscroll-behavior: none;
-}
-
-#spacer {
-  height: 200vh;
-  width: 200vw;
-}
-  </style>
-</head>
-<body>
-  <div id="scroller">
-    <div id="spacer">
-    </div>
-  </div>
-</body>
-<script>
-const searchParams = new URLSearchParams(location.search);
-
-async function test() {
-  var scrollendCount = 0;
-
-  // Add a scrollend event listener that counts the number of scrollend
-  // events fired to the scrollable element.
-  scroller.addEventListener("scrollend", () => {
-    scrollendCount += 1;
-  });
-
-  // Move the mouse over the scroller and perform a mouse click.
-  await promiseNativeMouseEventWithAPZ({
-    target: scroller,
-    offsetX: 10,
-    offsetY: 10,
-    type: "mousemove",
-  });
-
-  await promiseNativeMouseEventWithAPZ({
-    target: scroller,
-    offsetX: 10,
-    offsetY: 10,
-    type: "mousedown",
-  });
-
-  await promiseNativeMouseEventWithAPZ({
-    target: scroller,
-    offsetX: 10,
-    offsetY: 10,
-    type: "mouseup",
-  });
-
-  // Determine the arrow key value based on the value of "direction".
-  let key = null;
-  let direction = searchParams.get("direction");
-  switch (direction) {
-    case "up":
-      key = nativeArrowUpKey();
-      break;
-    case "down":
-      key = nativeArrowDownKey();
-      break;
-    default:
-      ok(false, "Unsupported direction value: " + direction);
-      break;
-  }
-
-  is(scrollendCount, 0, "A scrollend event should not be triggered yet");
-
-  // In order to exercise handling of keyboard events in APZ, we may
-  // want to flush repaints before the key input.
-  if (searchParams.has("flush-before-key")) {
-    await promiseApzFlushedRepaints();
-  }
-  await promiseFrame();
-
-  let transformEndPromise = promiseTransformEnd();
-
-  await new Promise(resolve => {
-    synthesizeNativeKey(KEYBOARD_LAYOUT_EN_US, key, {},
-                        "", "", resolve);
-  });
-
-  await promiseApzFlushedRepaints();
-
-  if (direction == "up") {
-    if (SpecialPowers.getBoolPref("general.smoothScroll")) {
-      // The smooth scroll animation with no distance should not be longer than
-      // half a second.
-      await new Promise(resolve => setTimeout(resolve, 500));
-    } else {
-      await promiseFrame();
-    }
-    is(scrollendCount, 0, "A user gesture with no scroll should have no scrollend");
-  } else {
-    if (SpecialPowers.getBoolPref("general.smoothScroll")) {
-      // If smooth scrolling is enabled and there is room to scroll, wait for the
-      // transform end notification.
-      await transformEndPromise;
-    }
-    await promiseFrame();
-    is(scrollendCount, 1, "A user gesture with a scroll should trigger a scrollend");
-  }
-}
-waitUntilApzStable()
-.then(test)
-.then(subtestDone, subtestFailed);
-</script>
-</html>

gfx/layers/apz/test/mochitest/test_group_scrollend.html

@@ -23,20 +23,8 @@ var prefs = [
 ];
 
 var smoothScrollDisabled = [
-  ...basePrefs,
-  ["general.smoothScroll", false],
-];
-
-var smoothMsdScrollEnabled = [
   ...basePrefs,
   ["general.smoothScroll", true],
-  ["general.smoothScroll.msdPhysics.enabled", true],
-];
-
-var smoothScrollEnabled = [
-  ...basePrefs,
-  ["general.smoothScroll", true],
-  ["general.smoothScroll.msdPhysics.enabled", false],
 ];
 
 var subtests = [
@@ -53,22 +41,6 @@ var subtests = [
         "prefs": smoothScrollDisabled},
   {"file": "helper_main_thread_smooth_scroll_scrollend.html",
         "prefs": smoothScrollDisabled},
-  {"file": "helper_keyboard_scrollend.html?direction=up",
-        "prefs": smoothMsdScrollEnabled},
-  {"file": "helper_keyboard_scrollend.html?direction=up",
-        "prefs": smoothScrollEnabled},
-  {"file": "helper_keyboard_scrollend.html?direction=up&flush-before-key",
-        "prefs": smoothScrollEnabled},
-  {"file": "helper_keyboard_scrollend.html?direction=up",
-        "prefs": smoothScrollDisabled},
-  {"file": "helper_keyboard_scrollend.html?direction=up&flush-before-key",
-        "prefs": smoothScrollDisabled},
-  {"file": "helper_keyboard_scrollend.html?direction=down&flush-before-key",
-        "prefs": smoothScrollEnabled},
-  {"file": "helper_keyboard_scrollend.html?direction=down&flush-before-key",
-        "prefs": smoothScrollDisabled},
-  {"file": "helper_keyboard_scrollend.html?direction=down",
-        "prefs": smoothScrollDisabled},
 ];
 
 if (isApzEnabled()) {