Backed out 8 changesets (bug 1610731) for reftest failures at dynamic-toolbar-fixed-bottom-1.html. CLOSED TREE

Backed out changeset a26b63d0248e (bug 1610731)
Backed out changeset c33e6fe22774 (bug 1610731)
Backed out changeset 840550c070e8 (bug 1610731)
Backed out changeset 7bffd6eb9ac7 (bug 1610731)
Backed out changeset a383a7100973 (bug 1610731)
Backed out changeset 8f2bae2ca274 (bug 1610731)
Backed out changeset 8d43fbe05f38 (bug 1610731)
Backed out changeset 035432f43d16 (bug 1610731)

--HG--
rename : layout/reftests/async-scrolling/dynamic-toolbar-sticky-top-1.html => layout/reftests/async-scrolling/dynamic-toolbar-fixed-bottom-1.html

gfx/ipc/GfxMessageUtils.h

@@ -569,31 +569,6 @@ struct ParamTraits<mozilla::gfx::RectTyped<T>> {
   }
 };
 
-template <class T>
-struct ParamTraits<mozilla::gfx::RectAbsoluteTyped<T>> {
-  typedef mozilla::gfx::RectAbsoluteTyped<T> paramType;
-
-  static void Write(Message* msg, const paramType& param) {
-    WriteParam(msg, param.Left());
-    WriteParam(msg, param.Right());
-    WriteParam(msg, param.Top());
-    WriteParam(msg, param.Bottom());
-  }
-
-  static bool Read(const Message* msg, PickleIterator* iter,
-                   paramType* result) {
-    auto l = result->Left();
-    auto r = result->Right();
-    auto t = result->Top();
-    auto b = result->Bottom();
-
-    bool retVal = (ReadParam(msg, iter, &l) && ReadParam(msg, iter, &r) &&
-                   ReadParam(msg, iter, &t) && ReadParam(msg, iter, &b));
-    result->SetBox(l, r, t, b);
-    return retVal;
-  }
-};
-
 template <class T>
 struct ParamTraits<mozilla::gfx::IntRectTyped<T>> {
   typedef mozilla::gfx::IntRectTyped<T> paramType;

gfx/layers/LayerMetricsWrapper.h

@@ -409,58 +409,38 @@ class MOZ_STACK_CLASS LayerMetricsWrapper final {
   ScrollableLayerGuid::ViewID GetFixedPositionScrollContainerId() const {
     MOZ_ASSERT(IsValid());
 
-    if (AtBottomLayer()) {
+    // TODO: Restrict this only for AtBottomLayer.
-      return mLayer->GetFixedPositionScrollContainerId();
+    return mLayer->GetFixedPositionScrollContainerId();
-    }
-    return ScrollableLayerGuid::NULL_SCROLL_ID;
   }
 
   SideBits GetFixedPositionSides() const {
     MOZ_ASSERT(IsValid());
 
-    if (AtBottomLayer()) {
+    return mLayer->GetFixedPositionSides();
-      return mLayer->GetFixedPositionSides();
+  }
-    }
+
-    return SideBits::eNone;
+  bool GetIsStickyPosition() const {
+    MOZ_ASSERT(IsValid());
+
+    return mLayer->GetIsStickyPosition();
   }
 
   ScrollableLayerGuid::ViewID GetStickyScrollContainerId() const {
     MOZ_ASSERT(IsValid());
 
-    if (AtBottomLayer() && mLayer->GetIsStickyPosition()) {
+    // TODO: Restrict this only for AtBottomLayer.
-      return mLayer->GetStickyScrollContainerId();
+    return mLayer->GetStickyScrollContainerId();
-    }
-    return ScrollableLayerGuid::NULL_SCROLL_ID;
   }
 
   const LayerRectAbsolute& GetStickyScrollRangeOuter() const {
     MOZ_ASSERT(IsValid());
 
-    if (AtBottomLayer() && mLayer->GetIsStickyPosition()) {
+    return mLayer->GetStickyScrollRangeOuter();
-      return mLayer->GetStickyScrollRangeOuter();
-    }
-
-    static const LayerRectAbsolute empty;
-    return empty;
   }
-
   const LayerRectAbsolute& GetStickyScrollRangeInner() const {
     MOZ_ASSERT(IsValid());
 
-    if (AtBottomLayer() && mLayer->GetIsStickyPosition()) {
+    return mLayer->GetStickyScrollRangeInner();
-      return mLayer->GetStickyScrollRangeInner();
-    }
-
-    static const LayerRectAbsolute empty;
-    return empty;
-  }
-
-  Maybe<uint64_t> GetStickyPositionAnimationId() const {
-    MOZ_ASSERT(IsValid());
-    // This function is only really needed for template-compatibility with
-    // WebRenderScrollDataWrapper. Although it will be called, the return
-    // value is not used.
-    return Nothing();
   }
 
   Maybe<uint64_t> GetZoomAnimationId() const {

gfx/layers/apz/src/APZCTreeManager.cpp

@@ -147,12 +147,16 @@ struct APZCTreeManager::TreeBuildingState {
   // codepath.
   Maybe<uint64_t> mZoomAnimationId;
 
-  // See corresponding members of APZCTreeManager. These are the same thing, but
+  // This is populated with all the HitTestingTreeNodes that have a fixed
-  // on the tree-walking state. They are populated while walking the tree in
+  // position animation id (which indicates that they need to be sampled for
-  // a layers update, and then moved into APZCTreeManager.
+  // WebRender on the sampler thread).
-  std::vector<FixedPositionInfo> mFixedPositionInfo;
+  std::vector<HitTestingTreeNode*> mFixedPositionNodesWithAnimationId;
-  std::vector<RootScrollbarInfo> mRootScrollbarInfo;
+
-  std::vector<StickyPositionInfo> mStickyPositionInfo;
+  // This is populated with all the HitTestingTreeNodes that are scrollbar
+  // containers for the root viewport and have a scrollthumb animation id
+  // (which indicates that they need to be sampled for WebRender on the sampler
+  // thread).
+  std::vector<HitTestingTreeNode*> mRootScrollbars;
 };
 
 class APZCTreeManager::CheckerboardFlushObserver : public nsIObserver {
@@ -473,23 +477,13 @@ APZCTreeManager::UpdateHitTestingTreeImpl(const ScrollNode& aRoot,
               state.mScrollThumbs.push_back(node);
             } else if (node->IsScrollbarContainerNode()) {
               // Only scrollbar containers for the root have an animation id.
-              state.mRootScrollbarInfo.emplace_back(
+              state.mRootScrollbars.push_back(node);
-                  *(node->GetScrollbarAnimationId()),
-                  node->GetScrollbarDirection());
             }
           }
 
           // GetFixedPositionAnimationId is only set when webrender is enabled.
           if (node->GetFixedPositionAnimationId().isSome()) {
-            state.mFixedPositionInfo.emplace_back(
+            state.mFixedPositionNodesWithAnimationId.push_back(node);
-                *(node->GetFixedPositionAnimationId()),
-                node->GetFixedPosSides());
-          }
-          // GetStickyPositionAnimationId is only set when webrender is enabled.
-          if (node->GetStickyPositionAnimationId().isSome()) {
-            state.mStickyPositionInfo.emplace_back(
-                *(node->GetStickyPositionAnimationId()),
-                node->GetFixedPosSides());
           }
           if (apzc && node->IsPrimaryHolder()) {
             state.mScrollTargets[apzc->GetGuid()] = node;
@@ -636,9 +630,26 @@ APZCTreeManager::UpdateHitTestingTreeImpl(const ScrollNode& aRoot,
           target->IsAncestorOf(thumb));
     }
 
-    mRootScrollbarInfo = std::move(state.mRootScrollbarInfo);
+    mRootScrollbarInfo.clear();
-    mFixedPositionInfo = std::move(state.mFixedPositionInfo);
+    // For non-webrender, and platforms without a dynamic toolbar,
-    mStickyPositionInfo = std::move(state.mStickyPositionInfo);
+    // state.mRootScrollbarsWithAnimationId will be empty so this will be a
+    // no-op.
+    for (const HitTestingTreeNode* scrollbar : state.mRootScrollbars) {
+      MOZ_ASSERT(scrollbar->IsScrollbarContainerNode());
+      mRootScrollbarInfo.emplace_back(*(scrollbar->GetScrollbarAnimationId()),
+                                      scrollbar->GetScrollbarDirection());
+    }
+
+    mFixedPositionInfo.clear();
+    // For non-webrender, state.mFixedPositionNodesWithAnimationId will be empty
+    // so this will be a no-op.
+    for (HitTestingTreeNode* fixedPos :
+         state.mFixedPositionNodesWithAnimationId) {
+      MOZ_ASSERT(fixedPos->GetFixedPositionAnimationId().isSome());
+      mFixedPositionInfo.emplace_back(
+          fixedPos->GetFixedPositionAnimationId().value(),
+          fixedPos->GetFixedPosSides());
+    }
   }
 
   for (size_t i = 0; i < state.mNodesToDestroy.Length(); i++) {
@@ -817,8 +828,7 @@ void APZCTreeManager::SampleForWebRender(
     if (info.mScrollDirection == ScrollDirection::eHorizontal) {
       ScreenPoint translation =
           AsyncCompositionManager::ComputeFixedMarginsOffset(
-              GetCompositorFixedLayerMargins(), SideBits::eBottom,
+              mCompositorFixedLayerMargins, SideBits::eBottom, ScreenMargin());
-              ScreenMargin());
 
       LayerToParentLayerMatrix4x4 transform =
           LayerToParentLayerMatrix4x4::Translation(ViewAs<ParentLayerPixel>(
@@ -832,7 +842,7 @@ void APZCTreeManager::SampleForWebRender(
   for (const FixedPositionInfo& info : mFixedPositionInfo) {
     ScreenPoint translation =
         AsyncCompositionManager::ComputeFixedMarginsOffset(
-            GetCompositorFixedLayerMargins(), info.mFixedPosSides,
+            mCompositorFixedLayerMargins, info.mFixedPosSides,
             mGeckoFixedLayerMargins);
 
     LayerToParentLayerMatrix4x4 transform =
@@ -843,23 +853,6 @@ void APZCTreeManager::SampleForWebRender(
         wr::ToWrTransformProperty(info.mFixedPositionAnimationId, transform));
   }
 
-  for (const StickyPositionInfo& info : mStickyPositionInfo) {
-    ScreenPoint translation =
-        AsyncCompositionManager::ComputeFixedMarginsOffset(
-            GetCompositorFixedLayerMargins(), info.mFixedPosSides,
-            // For sticky layers, we don't need to factor
-            // mGeckoFixedLayerMargins because Gecko doesn't shift the
-            // position of sticky elements for dynamic toolbar movements.
-            ScreenMargin());
-
-    LayerToParentLayerMatrix4x4 transform =
-        LayerToParentLayerMatrix4x4::Translation(ViewAs<ParentLayerPixel>(
-            translation, PixelCastJustification::ScreenIsParentLayerForRoot));
-
-    transforms.AppendElement(
-        wr::ToWrTransformProperty(info.mStickyPositionAnimationId, transform));
-  }
-
   aTxn.AppendTransformProperties(transforms);
 
   // Advance animations. It's important that this happens after
@@ -1200,10 +1193,14 @@ HitTestingTreeNode* APZCTreeManager::PrepareNodeForLayer(
     node->SetFixedPosData(aLayer.GetFixedPositionScrollContainerId(),
                           aLayer.GetFixedPositionSides(),
                           aLayer.GetFixedPositionAnimationId());
-    node->SetStickyPosData(aLayer.GetStickyScrollContainerId(),
+    if (aLayer.GetIsStickyPosition()) {
-                           aLayer.GetStickyScrollRangeOuter(),
+      node->SetStickyPosData(aLayer.GetStickyScrollContainerId(),
-                           aLayer.GetStickyScrollRangeInner(),
+                             aLayer.GetStickyScrollRangeOuter(),
-                           aLayer.GetStickyPositionAnimationId());
+                             aLayer.GetStickyScrollRangeInner());
+    } else {
+      node->SetStickyPosData(ScrollableLayerGuid::NULL_SCROLL_ID,
+                             LayerRectAbsolute(), LayerRectAbsolute());
+    }
     return node;
   }
 
@@ -1430,10 +1427,14 @@ HitTestingTreeNode* APZCTreeManager::PrepareNodeForLayer(
   node->SetFixedPosData(aLayer.GetFixedPositionScrollContainerId(),
                         aLayer.GetFixedPositionSides(),
                         aLayer.GetFixedPositionAnimationId());
-  node->SetStickyPosData(aLayer.GetStickyScrollContainerId(),
+  if (aLayer.GetIsStickyPosition()) {
-                         aLayer.GetStickyScrollRangeOuter(),
+    node->SetStickyPosData(aLayer.GetStickyScrollContainerId(),
-                         aLayer.GetStickyScrollRangeInner(),
+                           aLayer.GetStickyScrollRangeOuter(),
-                         aLayer.GetStickyPositionAnimationId());
+                           aLayer.GetStickyScrollRangeInner());
+  } else {
+    node->SetStickyPosData(ScrollableLayerGuid::NULL_SCROLL_ID,
+                           LayerRectAbsolute(), LayerRectAbsolute());
+  }
   return node;
 }
 
@@ -2103,7 +2104,7 @@ APZEventResult APZCTreeManager::ProcessTouchInput(MultiTouchInput& aInput) {
           MutexAutoLock lock(mMapLock);
           touchData.mScreenPoint -=
               RoundedToInt(AsyncCompositionManager::ComputeFixedMarginsOffset(
-                  GetCompositorFixedLayerMargins(), mFixedPosSidesForInputBlock,
+                  mCompositorFixedLayerMargins, mFixedPosSidesForInputBlock,
                   mGeckoFixedLayerMargins));
         }
       }
@@ -3391,7 +3392,7 @@ Maybe<ScreenIntPoint> APZCTreeManager::ConvertToGecko(
       MutexAutoLock mapLock(mMapLock);
       *geckoPoint -=
           RoundedToInt(AsyncCompositionManager::ComputeFixedMarginsOffset(
-              GetCompositorFixedLayerMargins(), mFixedPosSidesForInputBlock,
+              mCompositorFixedLayerMargins, mFixedPosSidesForInputBlock,
               mGeckoFixedLayerMargins));
     }
   }
@@ -3465,8 +3466,8 @@ bool APZCTreeManager::IsStuckToRootContentAtBottom(
     return false;
   }
 
-  // We support the dynamic toolbar at top and bottom.
+  // Currently we only support the dyanmic toolbar at bottom.
-  if ((aNode->GetFixedPosSides() & SideBits::eTopBottom) == SideBits::eNone) {
+  if ((aNode->GetFixedPosSides() & SideBits::eBottom) == SideBits::eNone) {
     return false;
   }
 
@@ -3561,7 +3562,7 @@ LayerToParentLayerMatrix4x4 APZCTreeManager::ComputeTransformForNode(
       MutexAutoLock mapLock(mMapLock);
       translation = ViewAs<ParentLayerPixel>(
           AsyncCompositionManager::ComputeFixedMarginsOffset(
-              GetCompositorFixedLayerMargins(), aNode->GetFixedPosSides(),
+              mCompositorFixedLayerMargins, aNode->GetFixedPosSides(),
               mGeckoFixedLayerMargins),
           PixelCastJustification::ScreenIsParentLayerForRoot);
     }
@@ -3574,8 +3575,8 @@ LayerToParentLayerMatrix4x4 APZCTreeManager::ComputeTransformForNode(
       MutexAutoLock mapLock(mMapLock);
       translation = ViewAs<ParentLayerPixel>(
           AsyncCompositionManager::ComputeFixedMarginsOffset(
-              GetCompositorFixedLayerMargins(),
+              mCompositorFixedLayerMargins,
-              aNode->GetFixedPosSides() & SideBits::eTopBottom,
+              aNode->GetFixedPosSides() & SideBits::eBottom,
               // For sticky layers, we don't need to factor
               // mGeckoFixedLayerMargins because Gecko doesn't shift the
               // position of sticky elements for dynamic toolbar movements.
@@ -3624,16 +3625,6 @@ already_AddRefed<GeckoContentController> APZCTreeManager::GetContentController(
   return controller.forget();
 }
 
-ScreenMargin APZCTreeManager::GetCompositorFixedLayerMargins() const {
-  RecursiveMutexAutoLock lock(mTreeLock);
-  ScreenMargin result = mCompositorFixedLayerMargins;
-  if (StaticPrefs::apz_fixed_margin_override_enabled()) {
-    result.top = StaticPrefs::apz_fixed_margin_override_top();
-    result.bottom = StaticPrefs::apz_fixed_margin_override_bottom();
-  }
-  return result;
-}
-
 bool APZCTreeManager::GetAPZTestData(LayersId aLayersId,
                                      APZTestData* aOutData) {
   AssertOnUpdaterThread();

gfx/layers/apz/src/APZCTreeManager.h

@@ -766,8 +766,6 @@ class APZCTreeManager : public IAPZCTreeManager, public APZInputBridge {
       const MutexAutoLock& aProofOfMapLock,
       ClippedCompositionBoundsMap& aDestMap, ScrollableLayerGuid aGuid);
 
-  ScreenMargin GetCompositorFixedLayerMargins() const;
-
  protected:
   /* The input queue where input events are held until we know enough to
    * figure out where they're going. Protected so gtests can access it.
@@ -818,8 +816,8 @@ class APZCTreeManager : public IAPZCTreeManager, public APZInputBridge {
    */
   bool mUsingAsyncZoomContainer;
 
-  /** A lock that protects mApzcMap, mScrollThumbInfo, mRootScrollbarInfo,
+  /** A lock that protects mApzcMap, mScrollThumbInfo, mRootScrollbarInfo, and
-   * mFixedPositionInfo, and mStickyPositionInfo.
+   * mFixedPositionInfo.
    */
   mutable mozilla::Mutex mMapLock;
 
@@ -935,32 +933,6 @@ class APZCTreeManager : public IAPZCTreeManager, public APZInputBridge {
    */
   std::vector<FixedPositionInfo> mFixedPositionInfo;
 
-  /**
-   * A helper structure to store all the information needed to compute the
-   * async transform for a sticky position element on the sampler thread.
-   */
-  struct StickyPositionInfo {
-    uint64_t mStickyPositionAnimationId;
-    SideBits mFixedPosSides;
-
-    StickyPositionInfo(const uint64_t& aStickyPositionAnimationId,
-                       const SideBits aFixedPosSides)
-        : mStickyPositionAnimationId(aStickyPositionAnimationId),
-          mFixedPosSides(aFixedPosSides) {}
-  };
-  /**
-   * If this APZCTreeManager is being used with WebRender, this vector gets
-   * populated during a layers update. It holds a package of information needed
-   * to compute and set the async transforms on sticky position content. This
-   * information is extracted from the HitTestingTreeNodes for the WebRender
-   * case because accessing the HitTestingTreeNodes requires holding the tree
-   * lock which we cannot do on the WR sampler thread. mStickyPositionInfo,
-   * however, can be accessed while just holding the mMapLock which is safe to
-   * do on the sampler thread. mMapLock must be acquired while accessing or
-   * modifying mStickyPositionInfo.
-   */
-  std::vector<StickyPositionInfo> mStickyPositionInfo;
-
   /* Holds the zoom constraints for scrollable layers, as determined by the
    * the main-thread gecko code. This can only be accessed on the updater
    * thread. */

gfx/layers/apz/src/HitTestingTreeNode.cpp

@@ -177,12 +177,10 @@ void HitTestingTreeNode::SetPrevSibling(HitTestingTreeNode* aSibling) {
 void HitTestingTreeNode::SetStickyPosData(
     ScrollableLayerGuid::ViewID aStickyPosTarget,
     const LayerRectAbsolute& aScrollRangeOuter,
-    const LayerRectAbsolute& aScrollRangeInner,
+    const LayerRectAbsolute& aScrollRangeInner) {
-    const Maybe<uint64_t>& aStickyPositionAnimationId) {
   mStickyPosTarget = aStickyPosTarget;
   mStickyScrollRangeOuter = aScrollRangeOuter;
   mStickyScrollRangeInner = aScrollRangeInner;
-  mStickyPositionAnimationId = aStickyPositionAnimationId;
 }
 
 ScrollableLayerGuid::ViewID HitTestingTreeNode::GetStickyPosTarget() const {
@@ -197,10 +195,6 @@ const LayerRectAbsolute& HitTestingTreeNode::GetStickyScrollRangeInner() const {
   return mStickyScrollRangeInner;
 }
 
-Maybe<uint64_t> HitTestingTreeNode::GetStickyPositionAnimationId() const {
-  return mStickyPositionAnimationId;
-}
-
 void HitTestingTreeNode::MakeRoot() {
   mParent = nullptr;
 

gfx/layers/apz/src/HitTestingTreeNode.h

@@ -136,12 +136,10 @@ class HitTestingTreeNode {
   /* Sticky pos info */
   void SetStickyPosData(ScrollableLayerGuid::ViewID aStickyPosTarget,
                         const LayerRectAbsolute& aScrollRangeOuter,
-                        const LayerRectAbsolute& aScrollRangeInner,
+                        const LayerRectAbsolute& aScrollRangeInner);
-                        const Maybe<uint64_t>& aStickyPositionAnimationId);
   ScrollableLayerGuid::ViewID GetStickyPosTarget() const;
   const LayerRectAbsolute& GetStickyScrollRangeOuter() const;
   const LayerRectAbsolute& GetStickyScrollRangeInner() const;
-  Maybe<uint64_t> GetStickyPositionAnimationId() const;
 
   /* Convert |aPoint| into the LayerPixel space for the layer corresponding to
    * this node. |aTransform| is the complete (content + async) transform for
@@ -207,9 +205,6 @@ class HitTestingTreeNode {
   ScrollableLayerGuid::ViewID mStickyPosTarget;
   LayerRectAbsolute mStickyScrollRangeOuter;
   LayerRectAbsolute mStickyScrollRangeInner;
-  // This is only set if WebRender is enabled. It holds the animation id that
-  // we use to adjust sticky position content for the toolbar.
-  Maybe<uint64_t> mStickyPositionAnimationId;
 
   /* Let {L,M} be the {layer, scrollable metrics} pair that this node
    * corresponds to in the layer tree. mEventRegions contains the event regions

gfx/layers/wr/WebRenderScrollData.cpp

@@ -23,7 +23,6 @@ WebRenderLayerScrollData::WebRenderLayerScrollData()
       mEventRegionsOverride(EventRegionsOverride::NoOverride),
       mFixedPositionSides(mozilla::SideBits::eNone),
       mFixedPosScrollContainerId(ScrollableLayerGuid::NULL_SCROLL_ID),
-      mStickyPosScrollContainerId(ScrollableLayerGuid::NULL_SCROLL_ID),
       mRenderRoot(wr::RenderRoot::Default) {}
 
 WebRenderLayerScrollData::~WebRenderLayerScrollData() = default;

gfx/layers/wr/WebRenderScrollData.h

@@ -124,34 +124,6 @@ class WebRenderLayerScrollData final {
     return mFixedPosScrollContainerId;
   }
 
-  void SetStickyPositionScrollContainerId(ScrollableLayerGuid::ViewID aId) {
-    mStickyPosScrollContainerId = aId;
-  }
-  ScrollableLayerGuid::ViewID GetStickyPositionScrollContainerId() const {
-    return mStickyPosScrollContainerId;
-  }
-
-  void SetStickyScrollRangeOuter(const LayerRectAbsolute& scrollRange) {
-    mStickyScrollRangeOuter = scrollRange;
-  }
-  const LayerRectAbsolute& GetStickyScrollRangeOuter() const {
-    return mStickyScrollRangeOuter;
-  }
-
-  void SetStickyScrollRangeInner(const LayerRectAbsolute& scrollRange) {
-    mStickyScrollRangeInner = scrollRange;
-  }
-  const LayerRectAbsolute& GetStickyScrollRangeInner() const {
-    return mStickyScrollRangeInner;
-  }
-
-  void SetStickyPositionAnimationId(const uint64_t& aId) {
-    mStickyPositionAnimationId = Some(aId);
-  }
-  Maybe<uint64_t> GetStickyPositionAnimationId() const {
-    return mStickyPositionAnimationId;
-  }
-
   wr::RenderRoot GetRenderRoot() { return mRenderRoot; }
 
   void SetZoomAnimationId(const uint64_t& aId) { mZoomAnimationId = Some(aId); }
@@ -199,10 +171,6 @@ class WebRenderLayerScrollData final {
   Maybe<uint64_t> mFixedPositionAnimationId;
   SideBits mFixedPositionSides;
   ScrollableLayerGuid::ViewID mFixedPosScrollContainerId;
-  ScrollableLayerGuid::ViewID mStickyPosScrollContainerId;
-  LayerRectAbsolute mStickyScrollRangeOuter;
-  LayerRectAbsolute mStickyScrollRangeInner;
-  Maybe<uint64_t> mStickyPositionAnimationId;
   wr::RenderRoot mRenderRoot;
   Maybe<uint64_t> mZoomAnimationId;
   Maybe<ScrollableLayerGuid::ViewID> mAsyncZoomContainerId;
@@ -306,10 +274,6 @@ struct ParamTraits<mozilla::layers::WebRenderLayerScrollData> {
     WriteParam(aMsg, aParam.mFixedPositionAnimationId);
     WriteParam(aMsg, aParam.mFixedPositionSides);
     WriteParam(aMsg, aParam.mFixedPosScrollContainerId);
-    WriteParam(aMsg, aParam.mStickyPosScrollContainerId);
-    WriteParam(aMsg, aParam.mStickyScrollRangeOuter);
-    WriteParam(aMsg, aParam.mStickyScrollRangeInner);
-    WriteParam(aMsg, aParam.mStickyPositionAnimationId);
     WriteParam(aMsg, aParam.mRenderRoot);
     WriteParam(aMsg, aParam.mZoomAnimationId);
     WriteParam(aMsg, aParam.mAsyncZoomContainerId);
@@ -331,10 +295,6 @@ struct ParamTraits<mozilla::layers::WebRenderLayerScrollData> {
            ReadParam(aMsg, aIter, &aResult->mFixedPositionAnimationId) &&
            ReadParam(aMsg, aIter, &aResult->mFixedPositionSides) &&
            ReadParam(aMsg, aIter, &aResult->mFixedPosScrollContainerId) &&
-           ReadParam(aMsg, aIter, &aResult->mStickyPosScrollContainerId) &&
-           ReadParam(aMsg, aIter, &aResult->mStickyScrollRangeOuter) &&
-           ReadParam(aMsg, aIter, &aResult->mStickyScrollRangeInner) &&
-           ReadParam(aMsg, aIter, &aResult->mStickyPositionAnimationId) &&
            ReadParam(aMsg, aIter, &aResult->mRenderRoot) &&
            ReadParam(aMsg, aIter, &aResult->mZoomAnimationId) &&
            ReadParam(aMsg, aIter, &aResult->mAsyncZoomContainerId);

gfx/layers/wr/WebRenderScrollDataWrapper.h

@@ -304,69 +304,46 @@ class MOZ_STACK_CLASS WebRenderScrollDataWrapper final {
 
   Maybe<uint64_t> GetFixedPositionAnimationId() const {
     MOZ_ASSERT(IsValid());
-
+    return mLayer->GetFixedPositionAnimationId();
-    if (AtBottomLayer()) {
-      return mLayer->GetFixedPositionAnimationId();
-    }
-    return Nothing();
   }
 
   ScrollableLayerGuid::ViewID GetFixedPositionScrollContainerId() const {
     MOZ_ASSERT(IsValid());
-
+    return mLayer->GetFixedPositionScrollContainerId();
-    if (AtBottomLayer()) {
-      return mLayer->GetFixedPositionScrollContainerId();
-    }
-    return ScrollableLayerGuid::NULL_SCROLL_ID;
   }
 
   SideBits GetFixedPositionSides() const {
     MOZ_ASSERT(IsValid());
+    return mLayer->GetFixedPositionSides();
+  }
 
-    if (AtBottomLayer()) {
+  bool GetIsStickyPosition() const {
-      return mLayer->GetFixedPositionSides();
+    MOZ_ASSERT(IsValid());
-    }
+
-    return SideBits::eNone;
+    // TODO: Bug 1610731 Implement this for WebRender.
+    return false;
   }
 
   ScrollableLayerGuid::ViewID GetStickyScrollContainerId() const {
     MOZ_ASSERT(IsValid());
 
-    if (AtBottomLayer()) {
+    // TODO: Bug 1610731 Implement this for WebRender.
-      return mLayer->GetStickyPositionScrollContainerId();
-    }
     return ScrollableLayerGuid::NULL_SCROLL_ID;
   }
 
   const LayerRectAbsolute& GetStickyScrollRangeOuter() const {
     MOZ_ASSERT(IsValid());
+    static const LayerRectAbsolute dummy;
 
-    if (AtBottomLayer()) {
+    // TODO: Bug 1610731 Implement this for WebRender.
-      return mLayer->GetStickyScrollRangeOuter();
+    return dummy;
-    }
-
-    static const LayerRectAbsolute empty;
-    return empty;
   }
-
   const LayerRectAbsolute& GetStickyScrollRangeInner() const {
     MOZ_ASSERT(IsValid());
+    static const LayerRectAbsolute dummy;
 
-    if (AtBottomLayer()) {
+    // TODO: Bug 1610731 Implement this for WebRender.
-      return mLayer->GetStickyScrollRangeInner();
+    return dummy;
-    }
-
-    static const LayerRectAbsolute empty;
-    return empty;
-  }
-
-  Maybe<uint64_t> GetStickyPositionAnimationId() const {
-    MOZ_ASSERT(IsValid());
-
-    if (AtBottomLayer()) {
-      return mLayer->GetStickyPositionAnimationId();
-    }
-    return Nothing();
   }
 
   Maybe<uint64_t> GetZoomAnimationId() const {

layout/painting/nsDisplayList.cpp

@@ -6873,12 +6873,13 @@ bool nsDisplayOwnLayer::IsScrollbarContainer() const {
          layers::ScrollbarLayerType::Container;
 }
 
-bool nsDisplayOwnLayer::IsRootScrollbarContainer() const {
+bool nsDisplayOwnLayer::IsRootScrollbarContainerWithDynamicToolbar() const {
   if (!IsScrollbarContainer()) {
     return false;
   }
 
   return mFrame->PresContext()->IsRootContentDocumentCrossProcess() &&
+         mFrame->PresContext()->HasDynamicToolbar() &&
          mScrollbarData.mTargetViewId ==
              nsLayoutUtils::ScrollIdForRootScrollFrame(mFrame->PresContext());
 }
@@ -6891,20 +6892,6 @@ bool nsDisplayOwnLayer::IsFixedPositionLayer() const {
   return GetType() == DisplayItemType::TYPE_FIXED_POSITION;
 }
 
-bool nsDisplayOwnLayer::IsStickyPositionLayer() const {
-  return GetType() == DisplayItemType::TYPE_STICKY_POSITION;
-}
-
-bool nsDisplayOwnLayer::HasDynamicToolbar() const {
-  if (!mFrame->PresContext()->IsRootContentDocumentCrossProcess()) {
-    return false;
-  }
-  return mFrame->PresContext()->HasDynamicToolbar() ||
-         // For tests on Android, this pref is set to simulate the dynamic
-         // toolbar
-         StaticPrefs::apz_fixed_margin_override_enabled();
-}
-
 // nsDisplayOpacity uses layers for rendering
 already_AddRefed<Layer> nsDisplayOwnLayer::BuildLayer(
     nsDisplayListBuilder* aBuilder, LayerManager* aManager,
@@ -6930,11 +6917,10 @@ bool nsDisplayOwnLayer::CreateWebRenderCommands(
     const StackingContextHelper& aSc, RenderRootStateManager* aManager,
     nsDisplayListBuilder* aDisplayListBuilder) {
   Maybe<wr::WrAnimationProperty> prop;
-  bool needsProp = aManager->LayerManager()->AsyncPanZoomEnabled() &&
+  bool needsProp =
-                   (IsScrollThumbLayer() || IsZoomingLayer() ||
+      aManager->LayerManager()->AsyncPanZoomEnabled() &&
-                    (IsFixedPositionLayer() && HasDynamicToolbar()) ||
+      (IsScrollThumbLayer() || IsZoomingLayer() || IsFixedPositionLayer() ||
-                    (IsStickyPositionLayer() && HasDynamicToolbar()) ||
+       IsRootScrollbarContainerWithDynamicToolbar());
-                    (IsRootScrollbarContainer() && HasDynamicToolbar()));
 
   if (needsProp) {
     // APZ is enabled and this is a scroll thumb or zooming layer, so we need
@@ -6972,11 +6958,8 @@ bool nsDisplayOwnLayer::CreateWebRenderCommands(
 bool nsDisplayOwnLayer::UpdateScrollData(
     mozilla::layers::WebRenderScrollData* aData,
     mozilla::layers::WebRenderLayerScrollData* aLayerData) {
-  bool isRelevantToApz =
+  bool isRelevantToApz = (IsScrollThumbLayer() || IsScrollbarContainer() ||
-      (IsScrollThumbLayer() || IsScrollbarContainer() || IsZoomingLayer() ||
+                          IsZoomingLayer() || IsFixedPositionLayer());
-       (IsFixedPositionLayer() && HasDynamicToolbar()) ||
-       (IsStickyPositionLayer() && HasDynamicToolbar()));
-
   if (!isRelevantToApz) {
     return false;
   }
@@ -6990,21 +6973,16 @@ bool nsDisplayOwnLayer::UpdateScrollData(
     return true;
   }
 
-  if (IsFixedPositionLayer() && HasDynamicToolbar()) {
+  if (IsFixedPositionLayer()) {
     aLayerData->SetFixedPositionAnimationId(mWrAnimationId);
     return true;
   }
 
-  if (IsStickyPositionLayer() && HasDynamicToolbar()) {
-    aLayerData->SetStickyPositionAnimationId(mWrAnimationId);
-    return true;
-  }
-
   MOZ_ASSERT(IsScrollbarContainer() || IsScrollThumbLayer());
 
   aLayerData->SetScrollbarData(mScrollbarData);
 
-  if (IsRootScrollbarContainer() && HasDynamicToolbar()) {
+  if (IsRootScrollbarContainerWithDynamicToolbar()) {
     aLayerData->SetScrollbarAnimationId(mWrAnimationId);
     return true;
   }
@@ -7346,8 +7324,7 @@ bool nsDisplayFixedPosition::UpdateScrollData(
     }
     aLayerData->SetFixedPositionScrollContainerId(GetScrollTargetId());
   }
-  nsDisplayOwnLayer::UpdateScrollData(aData, aLayerData);
+  return nsDisplayOwnLayer::UpdateScrollData(aData, aLayerData) | true;
-  return true;
 }
 
 void nsDisplayFixedPosition::WriteDebugInfo(std::stringstream& aStream) {
@@ -7467,11 +7444,23 @@ already_AddRefed<Layer> nsDisplayStickyPosition::BuildLayer(
       stickyScrollContainer->ScrollFrame()->GetScrolledFrame()->GetContent());
 
   float factor = presContext->AppUnitsPerDevPixel();
-  LayerRectAbsolute stickyOuter;
+  nsRectAbsolute outer;
-  LayerRectAbsolute stickyInner;
+  nsRectAbsolute inner;
-  CalculateLayerScrollRanges(
+  stickyScrollContainer->GetScrollRanges(mFrame, &outer, &inner);
-      stickyScrollContainer, factor, aContainerParameters.mXScale,
+  LayerRectAbsolute stickyOuter(
-      aContainerParameters.mYScale, stickyOuter, stickyInner);
+      NSAppUnitsToFloatPixels(outer.X(), factor) * aContainerParameters.mXScale,
+      NSAppUnitsToFloatPixels(outer.Y(), factor) * aContainerParameters.mYScale,
+      NSAppUnitsToFloatPixels(outer.XMost(), factor) *
+          aContainerParameters.mXScale,
+      NSAppUnitsToFloatPixels(outer.YMost(), factor) *
+          aContainerParameters.mYScale);
+  LayerRectAbsolute stickyInner(
+      NSAppUnitsToFloatPixels(inner.X(), factor) * aContainerParameters.mXScale,
+      NSAppUnitsToFloatPixels(inner.Y(), factor) * aContainerParameters.mYScale,
+      NSAppUnitsToFloatPixels(inner.XMost(), factor) *
+          aContainerParameters.mXScale,
+      NSAppUnitsToFloatPixels(inner.YMost(), factor) *
+          aContainerParameters.mYScale);
   layer->SetStickyPositionData(scrollId, stickyOuter, stickyInner);
 
   return layer.forget();
@@ -7491,7 +7480,11 @@ static nscoord DistanceToRange(nscoord min, nscoord max) {
   return 0;
 }
 
-StickyScrollContainer* nsDisplayStickyPosition::GetStickyScrollContainer() {
+bool nsDisplayStickyPosition::CreateWebRenderCommands(
+    mozilla::wr::DisplayListBuilder& aBuilder,
+    mozilla::wr::IpcResourceUpdateQueue& aResources,
+    const StackingContextHelper& aSc, RenderRootStateManager* aManager,
+    nsDisplayListBuilder* aDisplayListBuilder) {
   StickyScrollContainer* stickyScrollContainer =
       StickyScrollContainer::GetStickyScrollContainerForFrame(mFrame);
   if (stickyScrollContainer) {
@@ -7511,15 +7504,6 @@ StickyScrollContainer* nsDisplayStickyPosition::GetStickyScrollContainer() {
       stickyScrollContainer = nullptr;
     }
   }
-  return stickyScrollContainer;
-}
-
-bool nsDisplayStickyPosition::CreateWebRenderCommands(
-    mozilla::wr::DisplayListBuilder& aBuilder,
-    mozilla::wr::IpcResourceUpdateQueue& aResources,
-    const StackingContextHelper& aSc, RenderRootStateManager* aManager,
-    nsDisplayListBuilder* aDisplayListBuilder) {
-  StickyScrollContainer* stickyScrollContainer = GetStickyScrollContainer();
 
   Maybe<wr::SpaceAndClipChainHelper> saccHelper;
 
@@ -7655,7 +7639,7 @@ bool nsDisplayStickyPosition::CreateWebRenderCommands(
         wr::WrStackingContextClip::ClipChain(aBuilder.CurrentClipChainId());
     StackingContextHelper sc(aSc, GetActiveScrolledRoot(), mFrame, this,
                              aBuilder, params);
-    nsDisplayOwnLayer::CreateWebRenderCommands(aBuilder, aResources, sc,
+    nsDisplayWrapList::CreateWebRenderCommands(aBuilder, aResources, sc,
                                                aManager, aDisplayListBuilder);
   }
 
@@ -7666,62 +7650,6 @@ bool nsDisplayStickyPosition::CreateWebRenderCommands(
   return true;
 }
 
-void nsDisplayStickyPosition::CalculateLayerScrollRanges(
-    StickyScrollContainer* aStickyScrollContainer, float aAppUnitsPerDevPixel,
-    float aScaleX, float aScaleY, LayerRectAbsolute& aStickyOuter,
-    LayerRectAbsolute& aStickyInner) {
-  nsRectAbsolute outer;
-  nsRectAbsolute inner;
-  aStickyScrollContainer->GetScrollRanges(mFrame, &outer, &inner);
-  aStickyOuter.SetBox(
-      NSAppUnitsToFloatPixels(outer.X(), aAppUnitsPerDevPixel) * aScaleX,
-      NSAppUnitsToFloatPixels(outer.Y(), aAppUnitsPerDevPixel) * aScaleY,
-      NSAppUnitsToFloatPixels(outer.XMost(), aAppUnitsPerDevPixel) * aScaleX,
-      NSAppUnitsToFloatPixels(outer.YMost(), aAppUnitsPerDevPixel) * aScaleY);
-  aStickyInner.SetBox(
-      NSAppUnitsToFloatPixels(inner.X(), aAppUnitsPerDevPixel) * aScaleX,
-      NSAppUnitsToFloatPixels(inner.Y(), aAppUnitsPerDevPixel) * aScaleY,
-      NSAppUnitsToFloatPixels(inner.XMost(), aAppUnitsPerDevPixel) * aScaleX,
-      NSAppUnitsToFloatPixels(inner.YMost(), aAppUnitsPerDevPixel) * aScaleY);
-}
-
-bool nsDisplayStickyPosition::UpdateScrollData(
-    mozilla::layers::WebRenderScrollData* aData,
-    mozilla::layers::WebRenderLayerScrollData* aLayerData) {
-  bool hasDynamicToolbar = HasDynamicToolbar();
-  if (aLayerData && hasDynamicToolbar) {
-    StickyScrollContainer* stickyScrollContainer = GetStickyScrollContainer();
-    if (stickyScrollContainer) {
-      float auPerDevPixel = mFrame->PresContext()->AppUnitsPerDevPixel();
-      float cumulativeResolution =
-          mFrame->PresShell()->GetCumulativeResolution();
-      LayerRectAbsolute stickyOuter;
-      LayerRectAbsolute stickyInner;
-      CalculateLayerScrollRanges(stickyScrollContainer, auPerDevPixel,
-                                 cumulativeResolution, cumulativeResolution,
-                                 stickyOuter, stickyInner);
-      aLayerData->SetStickyScrollRangeOuter(stickyOuter);
-      aLayerData->SetStickyScrollRangeInner(stickyInner);
-
-      SideBits sides =
-          nsLayoutUtils::GetSideBitsForFixedPositionContent(mFrame);
-      aLayerData->SetFixedPositionSides(sides);
-
-      ViewID scrollId =
-          nsLayoutUtils::FindOrCreateIDFor(stickyScrollContainer->ScrollFrame()
-                                               ->GetScrolledFrame()
-                                               ->GetContent());
-      aLayerData->SetStickyPositionScrollContainerId(scrollId);
-    }
-  }
-  // Return true if either there is a dynamic toolbar affecting this sticky
-  // item or the OwnLayer base implementation returns true for some other
-  // reason.
-  bool ret = hasDynamicToolbar;
-  ret |= nsDisplayOwnLayer::UpdateScrollData(aData, aLayerData);
-  return ret;
-}
-
 nsDisplayScrollInfoLayer::nsDisplayScrollInfoLayer(
     nsDisplayListBuilder* aBuilder, nsIFrame* aScrolledFrame,
     nsIFrame* aScrollFrame, const CompositorHitTestInfo& aHitInfo,

layout/painting/nsDisplayList.h

@@ -49,7 +49,6 @@
 #include "nsAutoLayoutPhase.h"
 #include "nsDisplayItemTypes.h"
 #include "RetainedDisplayListHelpers.h"
-#include "Units.h"
 
 #include <stdint.h>
 #include "nsTHashtable.h"
@@ -78,7 +77,6 @@ class TransformReferenceBox;
 namespace mozilla {
 class FrameLayerBuilder;
 class PresShell;
-class StickyScrollContainer;
 namespace layers {
 struct FrameMetrics;
 class RenderRootStateManager;
@@ -6100,11 +6098,9 @@ class nsDisplayOwnLayer : public nsDisplayWrapList {
   nsDisplayOwnLayerFlags GetFlags() { return mFlags; }
   bool IsScrollThumbLayer() const;
   bool IsScrollbarContainer() const;
-  bool IsRootScrollbarContainer() const;
+  bool IsRootScrollbarContainerWithDynamicToolbar() const;
   bool IsZoomingLayer() const;
   bool IsFixedPositionLayer() const;
-  bool IsStickyPositionLayer() const;
-  bool HasDynamicToolbar() const;
 
  protected:
   nsDisplayOwnLayerFlags mFlags;
@@ -6239,23 +6235,11 @@ class nsDisplayStickyPosition : public nsDisplayOwnLayer {
       mozilla::layers::RenderRootStateManager* aManager,
       nsDisplayListBuilder* aDisplayListBuilder) override;
 
-  bool UpdateScrollData(
-      mozilla::layers::WebRenderScrollData* aData,
-      mozilla::layers::WebRenderLayerScrollData* aLayerData) override;
-
   const ActiveScrolledRoot* GetContainerASR() const { return mContainerASR; }
 
  private:
   NS_DISPLAY_ALLOW_CLONING()
 
-  void CalculateLayerScrollRanges(
-      mozilla::StickyScrollContainer* aStickyScrollContainer,
-      float aAppUnitsPerDevPixel, float aScaleX, float aScaleY,
-      mozilla::LayerRectAbsolute& aStickyOuter,
-      mozilla::LayerRectAbsolute& aStickyInner);
-
-  mozilla::StickyScrollContainer* GetStickyScrollContainer();
-
   // This stores the ASR that this sticky container item would have assuming it
   // has no fixed descendants. This may be the same as the ASR returned by
   // GetActiveScrolledRoot(), or it may be a descendant of that.

layout/reftests/async-scrolling/dynamic-toolbar-fixed-bottom-1.html

@@ -1,15 +1,15 @@
 <!DOCTYPE HTML>
 <!--
-  Tests that setting a fixed top margin in the compositor results
+  Tests that setting a fixed bottom margin in AsyncCompositionManager results
-  in the margin being applied to an element fixed to the top.
+  in the margin being applied to an element fixed to the bottom.
 
   The fixed margin is specified as a test-pref in reftest.list.
 
   The purpose of the fixed margin is to compensate for the transform that the
   dynamic toolbar applies to the entire content area. We don't have a way of
   simulating that transform in a reftest, so the fixed margin in isolation will
-  cause the fixed element to be offset from the top of the screen, and in
+  cause the fixed element to be offset from the bottom of the screen, and in
-  the ref page we use a regular CSS "margin-top" to match the rendering.
+  the ref page we use a regular CSS "margin-bottom" to match the rendering.
 -->
 <html>
 <meta name="viewport" content="width=device-width">
@@ -25,7 +25,7 @@ html {
     width: 100%;
     height: 200px;
     position: fixed;
-    top: 0;
+    bottom: 0;
     background: red;
 }
 </style>

layout/reftests/async-scrolling/dynamic-toolbar-fixed-top-1-ref.html

@@ -1,25 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<meta name="viewport" content="width=device-width">
-<style>
-html {
-    scrollbar-width: none;
-}
-#scrolled {
-    height: 2000px;
-    width: 100%;
-}
-#fixed {
-    width: 100%;
-    height: 200px;
-    position: fixed;
-    top: 0;
-    background: red;
-    margin-top: 50px;
-}
-</style>
-<body>
-  <div id="scrolled"></div>
-  <div id="fixed"></div>
-</body>
-</html>

layout/reftests/async-scrolling/dynamic-toolbar-sticky-bottom-1-ref.html

@@ -1,29 +0,0 @@
-<html>
-<meta name="viewport" content="width=device-width">
-<style>
-html {
-    scrollbar-width: none;
-}
-#scrolled {
-    display: flex;
-    justify-content: space-around;
-    align-items: flex-start;
-
-    height: 2000px;
-    width: 100%;
-}
-#sticky {
-    width: 100%;
-    height: 200px;
-    position: sticky;
-    bottom: 70px;
-    background: red;
-    align-self: flex-end;
-}
-</style>
-<body>
-  <div id="scrolled">
-    <div id="sticky"></div>
-  </div>
-</body>
-</html>

layout/reftests/async-scrolling/dynamic-toolbar-sticky-bottom-1.html

@@ -1,41 +0,0 @@
-<!DOCTYPE HTML>
-<!--
-  Tests that setting a fixed bottom margin in the compositor results
-  in the margin being applied to an element sticky to the bottom.
-
-  The fixed margin is specified as a test-pref in reftest.list.
-
-  The purpose of the fixed margin is to compensate for the transform that the
-  dynamic toolbar applies to the entire content area. We don't have a way of
-  simulating that transform in a reftest, so the fixed margin in isolation will
-  cause the sticky element to be offset from the bottom of the screen.
--->
-<html>
-<meta name="viewport" content="width=device-width">
-<style>
-html {
-    scrollbar-width: none;
-}
-#scrolled {
-    display: flex;
-    justify-content: space-around;
-    align-items: flex-start;
-
-    height: 2000px;
-    width: 100%;
-}
-#sticky {
-    width: 100%;
-    height: 200px;
-    position: sticky;
-    bottom: 20px;
-    background: red;
-    align-self: flex-end;
-}
-</style>
-<body>
-  <div id="scrolled">
-    <div id="sticky"></div>
-  </div>
-</body>
-</html>

layout/reftests/async-scrolling/dynamic-toolbar-sticky-top-1-ref.html

@@ -1,29 +0,0 @@
-<html>
-<meta name="viewport" content="width=device-width">
-<style>
-html {
-    scrollbar-width: none;
-}
-#scrolled {
-    display: flex;
-    justify-content: space-around;
-    align-items: flex-start;
-
-    height: 2000px;
-    width: 100%;
-}
-#sticky {
-    width: 100%;
-    height: 200px;
-    position: sticky;
-    top: 70px;
-    background: red;
-    align-self: flex-start;
-}
-</style>
-<body>
-  <div id="scrolled">
-    <div id="sticky"></div>
-  </div>
-</body>
-</html>

layout/reftests/async-scrolling/dynamic-toolbar-sticky-top-1.html

@@ -1,40 +0,0 @@
-<!DOCTYPE HTML>
-<!--
-  Tests that setting a fixed top margin in the compositor results
-  in the margin being applied to an element sticky to the top.
-
-  The fixed margin is specified as a test-pref in reftest.list.
-
-  The purpose of the fixed margin is to compensate for the transform that the
-  dynamic toolbar applies to the entire content area. We don't have a way of
-  simulating that transform in a reftest, so the fixed margin in isolation will
-  cause the fixed element to be offset from the top of the screen.
--->
-<html>
-<meta name="viewport" content="width=device-width">
-<style>
-html {
-    scrollbar-width: none;
-}
-#scrolled {
-    display: flex;
-    justify-content: space-around;
-    align-items: flex-start;
-
-    height: 2000px;
-    width: 100%;
-}
-#sticky {
-    width: 100%;
-    height: 200px;
-    position: sticky;
-    top: 20px;
-    background: red;
-}
-</style>
-<body>
-  <div id="scrolled">
-    <div id="sticky"></div>
-  </div>
-</body>
-</html>

layout/reftests/async-scrolling/reftest.list

@@ -98,7 +98,4 @@ fuzzy-if(!webrender,111-112,600-600) pref(apz.allow_zooming,true) == async-scrol
 
 # 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)
-skip-if(!Android) pref(apz.allow_zooming,true) test-pref(apz.fixed-margin-override.enabled,true) test-pref(apz.fixed-margin-override.bottom,50) == dynamic-toolbar-fixed-bottom-1.html dynamic-toolbar-fixed-bottom-1-ref.html
+skip-if(!Android) pref(apz.allow_zooming,true) test-pref(apz.fixed-margin-override.enabled,true) test-pref(apz.fixed-margin-override.bottom,50) fails-if(geckoview&&webrender) == dynamic-toolbar-fixed-bottom-1.html dynamic-toolbar-fixed-bottom-1-ref.html
-skip-if(!Android) pref(apz.allow_zooming,true) test-pref(apz.fixed-margin-override.enabled,true) test-pref(apz.fixed-margin-override.bottom,50) == dynamic-toolbar-sticky-bottom-1.html dynamic-toolbar-sticky-bottom-1-ref.html
-skip-if(!Android) pref(apz.allow_zooming,true) test-pref(apz.fixed-margin-override.enabled,true) test-pref(apz.fixed-margin-override.top,50) == dynamic-toolbar-fixed-top-1.html dynamic-toolbar-fixed-top-1-ref.html
-skip-if(!Android) pref(apz.allow_zooming,true) test-pref(apz.fixed-margin-override.enabled,true) test-pref(apz.fixed-margin-override.top,50) fails-if(geckoview&&!webrender) == dynamic-toolbar-sticky-top-1.html dynamic-toolbar-sticky-top-1-ref.html # bug 1627326 for geckoview&&!webrender