--- a/gfx/layers/wr/WebRenderLayerManager.cpp
+++ b/gfx/layers/wr/WebRenderLayerManager.cpp
@@ -233,16 +233,17 @@ WebRenderLayer::DumpLayerInfo(const char
                 Stringify(clip).c_str(),
                 Stringify(mixBlendMode).c_str());
 }
 
 WebRenderLayerManager::WebRenderLayerManager(nsIWidget* aWidget)
   : mWidget(aWidget)
   , mLatestTransactionId(0)
   , mNeedsComposite(false)
+  , mIsFirstPaint(false)
   , mTarget(nullptr)
 {
   MOZ_COUNT_CTOR(WebRenderLayerManager);
 }
 
 KnowsCompositor*
 WebRenderLayerManager::AsKnowsCompositor()
 {
@@ -376,18 +377,24 @@ WebRenderLayerManager::EndTransaction(Dr
   }
   DiscardCompositorAnimations();
   mRoot->StartPendingAnimations(mAnimationReadyTime);
 
   wr::DisplayListBuilder builder(WrBridge()->GetPipeline());
   WebRenderLayer::ToWebRenderLayer(mRoot)->RenderLayer(builder);
 
   WebRenderScrollData scrollData;
-  if (mRoot && mWidget->AsyncPanZoomEnabled()) {
-    PopulateScrollData(scrollData, mRoot.get());
+  if (mWidget->AsyncPanZoomEnabled()) {
+    if (mIsFirstPaint) {
+      scrollData.SetIsFirstPaint();
+      mIsFirstPaint = false;
+    }
+    if (mRoot) {
+      PopulateScrollData(scrollData, mRoot.get());
+    }
   }
 
   bool sync = mTarget != nullptr;
   mLatestTransactionId = mTransactionIdAllocator->GetTransactionId();
 
   WrBridge()->DPEnd(builder, size.ToUnknownSize(), sync, mLatestTransactionId, scrollData);
 
   MakeSnapshotIfRequired(size);

--- a/gfx/layers/wr/WebRenderLayerManager.h
+++ b/gfx/layers/wr/WebRenderLayerManager.h
@@ -138,16 +138,17 @@ public:
 
   virtual void Composite() override;
 
   virtual void SetNeedsComposite(bool aNeedsComposite) override
   {
     mNeedsComposite = aNeedsComposite;
   }
   virtual bool NeedsComposite() const override { return mNeedsComposite; }
+  virtual void SetIsFirstPaint() override { mIsFirstPaint = true; }
 
   DrawPaintedLayerCallback GetPaintedLayerCallback() const
   { return mPaintedLayerCallback; }
 
   void* GetPaintedLayerCallbackData() const
   { return mPaintedLayerCallbackData; }
 
   // adds an imagekey to a list of keys that will be discarded on the next
@@ -188,16 +189,17 @@ private:
   RefPtr<TransactionIdAllocator> mTransactionIdAllocator;
   uint64_t mLatestTransactionId;
 
   nsTArray<DidCompositeObserver*> mDidCompositeObservers;
 
   LayerRefArray mKeepAlive;
 
   bool mNeedsComposite;
+  bool mIsFirstPaint;
 
  // When we're doing a transaction in order to draw to a non-default
  // target, the layers transaction is only performed in order to send
  // a PLayers:Update.  We save the original non-default target to
  // mTarget, and then perform the transaction. After the transaction ends,
  // we send a message to our remote side to capture the actual pixels
  // being drawn to the default target, and then copy those pixels
  // back to mTarget.

--- a/gfx/layers/wr/WebRenderScrollData.cpp
+++ b/gfx/layers/wr/WebRenderScrollData.cpp
@@ -69,16 +69,17 @@ const ScrollMetadata&
 WebRenderLayerScrollData::GetScrollMetadata(const WebRenderScrollData& aOwner,
                                             size_t aIndex) const
 {
   MOZ_ASSERT(aIndex < mScrollIds.Length());
   return aOwner.GetScrollMetadata(mScrollIds[aIndex]);
 }
 
 WebRenderScrollData::WebRenderScrollData()
+  : mIsFirstPaint(false)
 {
 }
 
 WebRenderScrollData::~WebRenderScrollData()
 {
 }
 
 size_t
@@ -128,10 +129,22 @@ WebRenderScrollData::GetLayerData(size_t
 
 const ScrollMetadata&
 WebRenderScrollData::GetScrollMetadata(size_t aIndex) const
 {
   MOZ_ASSERT(aIndex < mScrollMetadatas.Length());
   return mScrollMetadatas[aIndex];
 }
 
+void
+WebRenderScrollData::SetIsFirstPaint()
+{
+  mIsFirstPaint = true;
+}
+
+bool
+WebRenderScrollData::IsFirstPaint() const
+{
+  return mIsFirstPaint;
+}
+
 } // namespace layers
 } // namespace mozilla

--- a/gfx/layers/wr/WebRenderScrollData.h
+++ b/gfx/layers/wr/WebRenderScrollData.h
@@ -111,16 +111,19 @@ public:
 
   // Return a pointer to the scroll data at the given index. Use with caution,
   // as the pointer may be invalidated if this WebRenderScrollData is mutated.
   WebRenderLayerScrollData* GetLayerDataMutable(size_t aIndex);
   const WebRenderLayerScrollData* GetLayerData(size_t aIndex) const;
 
   const ScrollMetadata& GetScrollMetadata(size_t aIndex) const;
 
+  void SetIsFirstPaint();
+  bool IsFirstPaint() const;
+
   friend struct IPC::ParamTraits<WebRenderScrollData>;
 
 private:
   // Internal data structure used to maintain uniqueness of mScrollMetadatas.
   // This is not serialized/deserialized over IPC because there's no need for it,
   // as the parent side doesn't need this at all. Also because we don't have any
   // IPC-friendly hashtable implementation lying around.
   // The key into this map is the scrollId of a ScrollMetadata, and the value is
@@ -133,16 +136,18 @@ private:
 
   // A list of per-layer scroll data objects, generated via a depth-first,
   // pre-order, last-to-first traversal of the layer tree (i.e. a recursive
   // traversal where a node N first pushes itself, followed by its children in
   // last-to-first order). Each layer's scroll data object knows how many
   // descendants that layer had, which allows reconstructing the traversal on the
   // other side.
   nsTArray<WebRenderLayerScrollData> mLayerScrollData;
+
+  bool mIsFirstPaint;
 };
 
 } // namespace layers
 } // namespace mozilla
 
 namespace IPC {
 
 template<>
@@ -192,21 +197,23 @@ struct ParamTraits<mozilla::layers::WebR
 {
   typedef mozilla::layers::WebRenderScrollData paramType;
 
   static void
   Write(Message* aMsg, const paramType& aParam)
   {
     WriteParam(aMsg, aParam.mScrollMetadatas);
     WriteParam(aMsg, aParam.mLayerScrollData);
+    WriteParam(aMsg, aParam.mIsFirstPaint);
   }
 
   static bool
   Read(const Message* aMsg, PickleIterator* aIter, paramType* aResult)
   {
     return ReadParam(aMsg, aIter, &aResult->mScrollMetadatas)
-        && ReadParam(aMsg, aIter, &aResult->mLayerScrollData);
+        && ReadParam(aMsg, aIter, &aResult->mLayerScrollData)
+        && ReadParam(aMsg, aIter, &aResult->mIsFirstPaint);
   }
 };
 
 } // namespace IPC
 
 #endif /* GFX_WEBRENDERSCROLLDATA_H */