Backed out changeset 30af8f80e275 (bug 1705927)for causing failures at test_group_hittest-2.html. a=backout

gfx/layers/FrameMetrics.h

@@ -820,7 +820,6 @@ struct ScrollMetadata {
         mResolutionUpdated(false),
         mIsRDMTouchSimulationActive(false),
         mDidContentGetPainted(true),
-        mPrefersReducedMotion(false),
         mOverscrollBehavior() {}
 
   bool operator==(const ScrollMetadata& aOther) const {
@@ -838,7 +837,6 @@ struct ScrollMetadata {
            mResolutionUpdated == aOther.mResolutionUpdated &&
            mIsRDMTouchSimulationActive == aOther.mIsRDMTouchSimulationActive &&
            mDidContentGetPainted == aOther.mDidContentGetPainted &&
-           mPrefersReducedMotion == aOther.mPrefersReducedMotion &&
            mDisregardedDirection == aOther.mDisregardedDirection &&
            mOverscrollBehavior == aOther.mOverscrollBehavior &&
            mScrollUpdates == aOther.mScrollUpdates;
@@ -926,9 +924,6 @@ struct ScrollMetadata {
     return mIsRDMTouchSimulationActive;
   }
 
-  void SetPrefersReducedMotion(bool aValue) { mPrefersReducedMotion = aValue; }
-  bool PrefersReducedMotion() const { return mPrefersReducedMotion; }
-
   bool DidContentGetPainted() const { return mDidContentGetPainted; }
 
  private:
@@ -1042,11 +1037,6 @@ struct ScrollMetadata {
   // can use the correct transforms.
   bool mDidContentGetPainted : 1;
 
-  // Whether the user has requested the system minimze the amount of
-  // non-essential motion it uses (see the prefers-reduced-motion
-  // media query).
-  bool mPrefersReducedMotion : 1;
-
   // The disregarded direction means the direction which is disregarded anyway,
   // even if the scroll frame overflows in that direction and the direction is
   // specified as scrollable. This could happen in some scenarios, for instance,

gfx/layers/apz/src/AsyncPanZoomController.cpp

@@ -5057,8 +5057,6 @@ void AsyncPanZoomController::NotifyLayersUpdated(
     mScrollMetadata.SetForceDisableApz(aScrollMetadata.IsApzForceDisabled());
     mScrollMetadata.SetIsRDMTouchSimulationActive(
         aScrollMetadata.GetIsRDMTouchSimulationActive());
-    mScrollMetadata.SetPrefersReducedMotion(
-        aScrollMetadata.PrefersReducedMotion());
     mScrollMetadata.SetDisregardedDirection(
         aScrollMetadata.GetDisregardedDirection());
     mScrollMetadata.SetOverscrollBehavior(

gfx/layers/apz/src/Overscroll.h

@@ -138,10 +138,6 @@ class GenericOverscrollEffect : public OverscrollEffectBase {
 
   void ConsumeOverscroll(ParentLayerPoint& aOverscroll,
                          ScrollDirections aOverscrolableDirections) override {
-    if (mApzc.mScrollMetadata.PrefersReducedMotion()) {
-      return;
-    }
-
     if (aOverscrolableDirections.contains(ScrollDirection::eHorizontal)) {
       mApzc.mX.OverscrollBy(aOverscroll.x);
       aOverscroll.x = 0;
@@ -159,10 +155,6 @@ class GenericOverscrollEffect : public OverscrollEffectBase {
 
   void HandleFlingOverscroll(const ParentLayerPoint& aVelocity,
                              SideBits aOverscrollSideBits) override {
-    if (mApzc.mScrollMetadata.PrefersReducedMotion()) {
-      return;
-    }
-
     mApzc.StartOverscrollAnimation(aVelocity, aOverscrollSideBits);
   }
 

gfx/layers/ipc/LayersMessageUtils.h

@@ -444,7 +444,6 @@ struct ParamTraits<mozilla::layers::ScrollMetadata>
     WriteParam(aMsg, aParam.mResolutionUpdated);
     WriteParam(aMsg, aParam.mIsRDMTouchSimulationActive);
     WriteParam(aMsg, aParam.mDidContentGetPainted);
-    WriteParam(aMsg, aParam.mPrefersReducedMotion);
     WriteParam(aMsg, aParam.mDisregardedDirection);
     WriteParam(aMsg, aParam.mOverscrollBehavior);
     WriteParam(aMsg, aParam.mScrollUpdates);
@@ -484,8 +483,6 @@ struct ParamTraits<mozilla::layers::ScrollMetadata>
                                 &paramType::SetIsRDMTouchSimulationActive)) &&
            ReadBoolForBitfield(aMsg, aIter, aResult,
                                &paramType::SetDidContentGetPainted) &&
-           ReadBoolForBitfield(aMsg, aIter, aResult,
-                               &paramType::SetPrefersReducedMotion) &&
            ReadParam(aMsg, aIter, &aResult->mDisregardedDirection) &&
            ReadParam(aMsg, aIter, &aResult->mOverscrollBehavior) &&
            ReadParam(aMsg, aIter, &aResult->mScrollUpdates);

layout/base/nsLayoutUtils.cpp

@@ -35,7 +35,6 @@
 #include "mozilla/BasicEvents.h"
 #include "mozilla/ClearOnShutdown.h"
 #include "mozilla/DisplayPortUtils.h"
-#include "mozilla/GeckoBindings.h"
 #include "mozilla/dom/AnonymousContent.h"
 #include "mozilla/dom/BrowserChild.h"
 #include "mozilla/dom/CanvasUtils.h"
@@ -8783,9 +8782,6 @@ ScrollMetadata nsLayoutUtils::ComputeScrollMetadata(
     metadata.SetForceDisableApz(true);
   }
 
-  metadata.SetPrefersReducedMotion(
-      Gecko_MediaFeatures_PrefersReducedMotion(document));
-
   return metadata;
 }
 

layout/reftests/async-scrolling/no-overscroll-ref.html

@@ -1,24 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-  <style>
-    html {
-      scrollbar-width: none;
-    }
-    body {
-      height: 3000px;
-      margin: 0;
-    }
-    div {
-      position: absolute;
-      top: 0px;
-      width: 200px;
-      height: 200px;
-      background: green;
-    }
-  </style>
-</head>
-<body>
-  <div></div>
-</body>
-</html>

layout/reftests/async-scrolling/overscroll-reduced-motion.html

@@ -1,39 +0,0 @@
-<!DOCTYPE html>
-<html
-      reftest-async-scroll
-      reftest-displayport-x="0" reftest-displayport-y="0"
-      reftest-displayport-w="800" reftest-displayport-h="2000"
-      reftest-async-scroll-x="0" reftest-async-scroll-y="-200">
-<head>
-  <style>
-    html {
-      scrollbar-width: none;
-    }
-    body {
-      height: 3000px;
-      margin: 0;
-    }
-    div {
-      position: absolute;
-      top: 0px;
-      width: 200px;
-      height: 200px;
-      background: green;
-    }
-  </style>
-</head>
-<body >
-  <!-- Test that an overscroll past one end of a viewport is rendered
-      as having the content create a gutter, and that
-      the overscroll is reduced by some factor such that 
-      a 100px scroll must produce a rendered translation of less than
-      100px.
-
-      Current overscroll physics mean that an instantaneous overscroll
-      by 200px produces an 8px gutter. This is governed by the logic in
-      Axis::ApplyResistance(); if that logic is changed, this test will
-      need to be modified to account for the new result.
-  -->
-  <div></div>
-</body>
-</html>

layout/reftests/async-scrolling/reftest.list

@@ -99,7 +99,6 @@ fuzzy-if(!webrender,111-112,600-600) pref(apz.allow_zooming,true) == async-scrol
 
 # on Android we have a different overscroll effect so this test is disabled
 skip-if(!asyncPan||Android) pref(apz.overscroll.enabled,true) pref(apz.overscroll.test_async_scroll_offset.enabled,true) == overscroll.html overscroll-ref.html
-skip-if(!asyncPan||Android) pref(ui.prefersReducedMotion,1) pref(apz.overscroll.enabled,true) pref(apz.overscroll.test_async_scroll_offset.enabled,true) == overscroll-reduced-motion.html no-overscroll-ref.html
 
 # for this test, apz.allow_zooming is needed to ensure we take the containerless scrolling codepath that creates
 # an async zoom container (since we are testing a regression in that codepath)