diff --git a/gfx/layers/apz/public/APZSampler.h b/gfx/layers/apz/public/APZSampler.h
index ae8695b46286..fcf2015ce647 100644
--- a/gfx/layers/apz/public/APZSampler.h
+++ b/gfx/layers/apz/public/APZSampler.h
@@ -63,6 +63,13 @@ public:
 
   bool GetAPZTestData(uint64_t aLayersId, APZTestData* aOutData);
 
+  void SetTestAsyncScrollOffset(uint64_t aLayersId,
+                                const FrameMetrics::ViewID& aScrollId,
+                                const CSSPoint& aOffset);
+  void SetTestAsyncZoom(uint64_t aLayersId,
+                        const FrameMetrics::ViewID& aScrollId,
+                        const LayerToParentLayerScale& aZoom);
+
 protected:
   virtual ~APZSampler();
 
diff --git a/gfx/layers/apz/src/APZSampler.cpp b/gfx/layers/apz/src/APZSampler.cpp
index 304441638855..3a542c3867a7 100644
--- a/gfx/layers/apz/src/APZSampler.cpp
+++ b/gfx/layers/apz/src/APZSampler.cpp
@@ -95,5 +95,33 @@ APZSampler::GetAPZTestData(uint64_t aLayersId,
   return mApz->GetAPZTestData(aLayersId, aOutData);
 }
 
+void
+APZSampler::SetTestAsyncScrollOffset(uint64_t aLayersId,
+                                     const FrameMetrics::ViewID& aScrollId,
+                                     const CSSPoint& aOffset)
+{
+  MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread());
+  RefPtr<AsyncPanZoomController> apzc = mApz->GetTargetAPZC(aLayersId, aScrollId);
+  if (apzc) {
+    apzc->SetTestAsyncScrollOffset(aOffset);
+  } else {
+    NS_WARNING("Unable to find APZC in SetTestAsyncScrollOffset");
+  }
+}
+
+void
+APZSampler::SetTestAsyncZoom(uint64_t aLayersId,
+                             const FrameMetrics::ViewID& aScrollId,
+                             const LayerToParentLayerScale& aZoom)
+{
+  MOZ_ASSERT(CompositorThreadHolder::IsInCompositorThread());
+  RefPtr<AsyncPanZoomController> apzc = mApz->GetTargetAPZC(aLayersId, aScrollId);
+  if (apzc) {
+    apzc->SetTestAsyncZoom(aZoom);
+  } else {
+    NS_WARNING("Unable to find APZC in SetTestAsyncZoom");
+  }
+}
+
 } // namespace layers
 } // namespace mozilla
diff --git a/gfx/layers/ipc/CompositorBridgeParent.cpp b/gfx/layers/ipc/CompositorBridgeParent.cpp
index d628ec9f1f21..61108cd2eb3d 100644
--- a/gfx/layers/ipc/CompositorBridgeParent.cpp
+++ b/gfx/layers/ipc/CompositorBridgeParent.cpp
@@ -1378,6 +1378,30 @@ CompositorBridgeParent::RecvGetFrameUniformity(FrameUniformityData* aOutData)
   return IPC_OK();
 }
 
+void
+CompositorBridgeParent::SetTestAsyncScrollOffset(
+    const uint64_t& aLayersId,
+    const FrameMetrics::ViewID& aScrollId,
+    const CSSPoint& aPoint)
+{
+  if (mApzSampler) {
+    uint64_t layersId = (aLayersId == 0 ? mRootLayerTreeID : aLayersId);
+    mApzSampler->SetTestAsyncScrollOffset(layersId, aScrollId, aPoint);
+  }
+}
+
+void
+CompositorBridgeParent::SetTestAsyncZoom(
+    const uint64_t& aLayersId,
+    const FrameMetrics::ViewID& aScrollId,
+    const LayerToParentLayerScale& aZoom)
+{
+  if (mApzSampler) {
+    uint64_t layersId = (aLayersId == 0 ? mRootLayerTreeID : aLayersId);
+    mApzSampler->SetTestAsyncZoom(layersId, aScrollId, aZoom);
+  }
+}
+
 void
 CompositorBridgeParent::FlushApzRepaints(const uint64_t& aLayersId)
 {
diff --git a/gfx/layers/ipc/CompositorBridgeParent.h b/gfx/layers/ipc/CompositorBridgeParent.h
index d68107b91eed..a244d83d7e20 100644
--- a/gfx/layers/ipc/CompositorBridgeParent.h
+++ b/gfx/layers/ipc/CompositorBridgeParent.h
@@ -114,6 +114,12 @@ public:
                                  const TimeStamp& aTime) { return true; }
   virtual void LeaveTestMode(const uint64_t& aId) { }
   virtual void ApplyAsyncProperties(LayerTransactionParent* aLayerTree) = 0;
+  virtual void SetTestAsyncScrollOffset(const uint64_t& aLayersId,
+                                        const FrameMetrics::ViewID& aScrollId,
+                                        const CSSPoint& aPoint) = 0;
+  virtual void SetTestAsyncZoom(const uint64_t& aLayersId,
+                                const FrameMetrics::ViewID& aScrollId,
+                                const LayerToParentLayerScale& aZoom) = 0;
   virtual void FlushApzRepaints(const uint64_t& aLayersId) = 0;
   virtual void GetAPZTestData(const uint64_t& aLayersId,
                               APZTestData* aOutData) { }
@@ -248,6 +254,12 @@ public:
   void LeaveTestMode(const uint64_t& aId) override;
   void ApplyAsyncProperties(LayerTransactionParent* aLayerTree) override;
   CompositorAnimationStorage* GetAnimationStorage();
+  void SetTestAsyncScrollOffset(const uint64_t& aLayersId,
+                                const FrameMetrics::ViewID& aScrollId,
+                                const CSSPoint& aPoint) override;
+  void SetTestAsyncZoom(const uint64_t& aLayersId,
+                        const FrameMetrics::ViewID& aScrollId,
+                        const LayerToParentLayerScale& aZoom) override;
   void FlushApzRepaints(const uint64_t& aLayersId) override;
   void GetAPZTestData(const uint64_t& aLayersId,
                       APZTestData* aOutData) override;
diff --git a/gfx/layers/ipc/CrossProcessCompositorBridgeParent.cpp b/gfx/layers/ipc/CrossProcessCompositorBridgeParent.cpp
index 69d78c3df0f2..35eb0334e432 100644
--- a/gfx/layers/ipc/CrossProcessCompositorBridgeParent.cpp
+++ b/gfx/layers/ipc/CrossProcessCompositorBridgeParent.cpp
@@ -463,6 +463,40 @@ CrossProcessCompositorBridgeParent::ApplyAsyncProperties(
   state->mParent->ApplyAsyncProperties(aLayerTree);
 }
 
+void
+CrossProcessCompositorBridgeParent::SetTestAsyncScrollOffset(
+    const uint64_t& aLayersId,
+    const FrameMetrics::ViewID& aScrollId,
+    const CSSPoint& aPoint)
+{
+  MOZ_ASSERT(aLayersId != 0);
+  const CompositorBridgeParent::LayerTreeState* state =
+    CompositorBridgeParent::GetIndirectShadowTree(aLayersId);
+  if (!state) {
+    return;
+  }
+
+  MOZ_ASSERT(state->mParent);
+  state->mParent->SetTestAsyncScrollOffset(aLayersId, aScrollId, aPoint);
+}
+
+void
+CrossProcessCompositorBridgeParent::SetTestAsyncZoom(
+    const uint64_t& aLayersId,
+    const FrameMetrics::ViewID& aScrollId,
+    const LayerToParentLayerScale& aZoom)
+{
+  MOZ_ASSERT(aLayersId != 0);
+  const CompositorBridgeParent::LayerTreeState* state =
+    CompositorBridgeParent::GetIndirectShadowTree(aLayersId);
+  if (!state) {
+    return;
+  }
+
+  MOZ_ASSERT(state->mParent);
+  state->mParent->SetTestAsyncZoom(aLayersId, aScrollId, aZoom);
+}
+
 void
 CrossProcessCompositorBridgeParent::FlushApzRepaints(const uint64_t& aLayersId)
 {
diff --git a/gfx/layers/ipc/CrossProcessCompositorBridgeParent.h b/gfx/layers/ipc/CrossProcessCompositorBridgeParent.h
index 2d7da3ac5bab..1622574d59da 100644
--- a/gfx/layers/ipc/CrossProcessCompositorBridgeParent.h
+++ b/gfx/layers/ipc/CrossProcessCompositorBridgeParent.h
@@ -95,6 +95,12 @@ public:
                          const TimeStamp& aTime) override;
   void LeaveTestMode(const uint64_t& aId) override;
   void ApplyAsyncProperties(LayerTransactionParent* aLayerTree) override;
+  void SetTestAsyncScrollOffset(const uint64_t& aLayersId,
+                                const FrameMetrics::ViewID& aScrollId,
+                                const CSSPoint& aPoint) override;
+  void SetTestAsyncZoom(const uint64_t& aLayersId,
+                        const FrameMetrics::ViewID& aScrollId,
+                        const LayerToParentLayerScale& aZoom) override;
   void FlushApzRepaints(const uint64_t& aLayersId) override;
   void GetAPZTestData(const uint64_t& aLayersId,
                       APZTestData* aOutData) override;
diff --git a/gfx/layers/ipc/LayerTransactionParent.cpp b/gfx/layers/ipc/LayerTransactionParent.cpp
index dc043ce78c14..b0d24e86456c 100644
--- a/gfx/layers/ipc/LayerTransactionParent.cpp
+++ b/gfx/layers/ipc/LayerTransactionParent.cpp
@@ -6,7 +6,6 @@
 
 #include "LayerTransactionParent.h"
 #include <vector>                       // for vector
-#include "apz/src/AsyncPanZoomController.h"
 #include "CompositableHost.h"           // for CompositableParent, Get, etc
 #include "ImageLayers.h"                // for ImageLayer
 #include "Layers.h"                     // for Layer, ContainerLayer, etc
@@ -751,25 +750,6 @@ LayerTransactionParent::RecvGetAnimationTransform(const uint64_t& aCompositorAni
   return IPC_OK();
 }
 
-static AsyncPanZoomController*
-GetAPZCForViewID(Layer* aLayer, FrameMetrics::ViewID aScrollID)
-{
-  AsyncPanZoomController* resultApzc = nullptr;
-  ForEachNode<ForwardIterator>(
-      aLayer,
-      [aScrollID, &resultApzc] (Layer* layer)
-      {
-        for (uint32_t i = 0; i < layer->GetScrollMetadataCount(); i++) {
-          if (layer->GetFrameMetrics(i).GetScrollId() == aScrollID) {
-            resultApzc = layer->GetAsyncPanZoomController(i);
-            return TraversalFlag::Abort;
-          }
-        }
-        return TraversalFlag::Continue;
-      });
-  return resultApzc;
-}
-
 mozilla::ipc::IPCResult
 LayerTransactionParent::RecvSetAsyncScrollOffset(const FrameMetrics::ViewID& aScrollID,
                                                  const float& aX, const float& aY)
@@ -778,11 +758,7 @@ LayerTransactionParent::RecvSetAsyncScrollOffset(const FrameMetrics::ViewID& aSc
     return IPC_FAIL_NO_REASON(this);
   }
 
-  AsyncPanZoomController* controller = GetAPZCForViewID(mRoot, aScrollID);
-  if (!controller) {
-    return IPC_FAIL_NO_REASON(this);
-  }
-  controller->SetTestAsyncScrollOffset(CSSPoint(aX, aY));
+  mCompositorBridge->SetTestAsyncScrollOffset(GetId(), aScrollID, CSSPoint(aX, aY));
   return IPC_OK();
 }
 
@@ -794,11 +770,7 @@ LayerTransactionParent::RecvSetAsyncZoom(const FrameMetrics::ViewID& aScrollID,
     return IPC_FAIL_NO_REASON(this);
   }
 
-  AsyncPanZoomController* controller = GetAPZCForViewID(mRoot, aScrollID);
-  if (!controller) {
-    return IPC_FAIL_NO_REASON(this);
-  }
-  controller->SetTestAsyncZoom(LayerToParentLayerScale(aValue));
+  mCompositorBridge->SetTestAsyncZoom(GetId(), aScrollID, LayerToParentLayerScale(aValue));
   return IPC_OK();
 }
 
diff --git a/gfx/layers/wr/WebRenderBridgeParent.cpp b/gfx/layers/wr/WebRenderBridgeParent.cpp
index c4554496105d..16574dbcfdd9 100644
--- a/gfx/layers/wr/WebRenderBridgeParent.cpp
+++ b/gfx/layers/wr/WebRenderBridgeParent.cpp
@@ -6,7 +6,6 @@
 
 #include "mozilla/layers/WebRenderBridgeParent.h"
 
-#include "apz/src/AsyncPanZoomController.h"
 #include "CompositableHost.h"
 #include "gfxEnv.h"
 #include "gfxPrefs.h"
@@ -16,7 +15,6 @@
 #include "GLContextProvider.h"
 #include "mozilla/Range.h"
 #include "mozilla/layers/AnimationHelper.h"
-#include "mozilla/layers/APZCTreeManager.h"
 #include "mozilla/layers/APZSampler.h"
 #include "mozilla/layers/Compositor.h"
 #include "mozilla/layers/CompositorBridgeParent.h"
@@ -1017,18 +1015,6 @@ WebRenderBridgeParent::RecvCapture()
   return IPC_OK();
 }
 
-already_AddRefed<AsyncPanZoomController>
-WebRenderBridgeParent::GetTargetAPZC(const FrameMetrics::ViewID& aScrollId)
-{
-  RefPtr<AsyncPanZoomController> apzc;
-  if (CompositorBridgeParent* cbp = GetRootCompositorBridgeParent()) {
-    if (RefPtr<APZCTreeManager> apzctm = cbp->GetAPZCTreeManager()) {
-      apzc = apzctm->GetTargetAPZC(GetLayersId(), aScrollId);
-    }
-  }
-  return apzc.forget();
-}
-
 mozilla::ipc::IPCResult
 WebRenderBridgeParent::RecvSetConfirmedTargetAPZC(const uint64_t& aBlockId,
                                                   nsTArray<ScrollableLayerGuid>&& aTargets)
@@ -1106,11 +1092,7 @@ WebRenderBridgeParent::RecvSetAsyncScrollOffset(const FrameMetrics::ViewID& aScr
   if (mDestroyed) {
     return IPC_OK();
   }
-  RefPtr<AsyncPanZoomController> apzc = GetTargetAPZC(aScrollId);
-  if (!apzc) {
-    return IPC_FAIL_NO_REASON(this);
-  }
-  apzc->SetTestAsyncScrollOffset(CSSPoint(aX, aY));
+  mCompositorBridge->SetTestAsyncScrollOffset(GetLayersId(), aScrollId, CSSPoint(aX, aY));
   return IPC_OK();
 }
 
@@ -1121,11 +1103,7 @@ WebRenderBridgeParent::RecvSetAsyncZoom(const FrameMetrics::ViewID& aScrollId,
   if (mDestroyed) {
     return IPC_OK();
   }
-  RefPtr<AsyncPanZoomController> apzc = GetTargetAPZC(aScrollId);
-  if (!apzc) {
-    return IPC_FAIL_NO_REASON(this);
-  }
-  apzc->SetTestAsyncZoom(LayerToParentLayerScale(aZoom));
+  mCompositorBridge->SetTestAsyncZoom(GetLayersId(), aScrollId, LayerToParentLayerScale(aZoom));
   return IPC_OK();
 }
 
diff --git a/gfx/layers/wr/WebRenderBridgeParent.h b/gfx/layers/wr/WebRenderBridgeParent.h
index 825b8c82286a..452a3454283a 100644
--- a/gfx/layers/wr/WebRenderBridgeParent.h
+++ b/gfx/layers/wr/WebRenderBridgeParent.h
@@ -228,10 +228,6 @@ private:
   bool PushAPZStateToWR(wr::TransactionBuilder& aTxn,
                         nsTArray<wr::WrTransformProperty>& aTransformArray);
 
-  // Helper method to get an APZC reference from a scroll id. Uses the layers
-  // id of this bridge, and may return null if the APZC wasn't found.
-  already_AddRefed<AsyncPanZoomController> GetTargetAPZC(const FrameMetrics::ViewID& aId);
-
   uint32_t GetNextWrEpoch();
 
 private: