--- a/gfx/layers/wr/WebRenderBridgeParent.cpp
+++ b/gfx/layers/wr/WebRenderBridgeParent.cpp
@@ -614,18 +614,19 @@ WebRenderBridgeParent::RecvSetDisplayLis
   // to early-return from RecvDPEnd without doing so.
   AutoWebRenderBridgeParentAsyncMessageSender autoAsyncMessageSender(this, &aToDestroy);
 
   wr::Epoch wrEpoch = GetNextWrEpoch();
 
   mAsyncImageManager->SetCompositionTime(TimeStamp::Now());
 
   wr::TransactionBuilder txn;
+  wr::AutoTransactionSender sender(mApi, &txn);
+
   ProcessWebRenderParentCommands(aCommands, txn);
-  mApi->SendTransaction(txn);
 
   if (!UpdateResources(aResourceUpdates, aSmallShmems, aLargeShmems, txn)) {
     return IPC_FAIL(this, "Failed to deserialize resource updates");
   }
 
   mReceivedDisplayList = true;
 
   // aScrollData is moved into this function but that is not reflected by the

--- a/gfx/webrender_bindings/WebRenderAPI.h
+++ b/gfx/webrender_bindings/WebRenderAPI.h
@@ -232,16 +232,40 @@ protected:
   // for each document).
   RefPtr<wr::WebRenderAPI> mRootApi;
   RefPtr<wr::WebRenderAPI> mRootDocumentApi;
 
   friend class DisplayListBuilder;
   friend class layers::WebRenderBridgeParent;
 };
 
+// This is a RAII class that automatically sends the transaction on
+// destruction. This is useful for code that has multiple exit points and we
+// want to ensure that the stuff accumulated in the transaction gets sent
+// regardless of which exit we take. Note that if the caller explicitly calls
+// mApi->SendTransaction() that's fine too because that empties out the
+// TransactionBuilder and leaves it as a valid empty transaction, so calling
+// SendTransaction on it again ends up being a no-op.
+class MOZ_RAII AutoTransactionSender
+{
+public:
+  AutoTransactionSender(WebRenderAPI* aApi, TransactionBuilder* aTxn)
+    : mApi(aApi)
+    , mTxn(aTxn)
+  {}
+
+  ~AutoTransactionSender() {
+    mApi->SendTransaction(*mTxn);
+  }
+
+private:
+  WebRenderAPI* mApi;
+  TransactionBuilder* mTxn;
+};
+
 /// This is a simple C++ wrapper around WrState defined in the rust bindings.
 /// We may want to turn this into a direct wrapper on top of WebRenderFrameBuilder
 /// instead, so the interface may change a bit.
 class DisplayListBuilder {
 public:
   explicit DisplayListBuilder(wr::PipelineId aId,
                               const wr::LayoutSize& aContentSize,
                               size_t aCapacity = 0);