--- a/gfx/layers/wr/StackingContextHelper.cpp
+++ b/gfx/layers/wr/StackingContextHelper.cpp
@@ -21,19 +21,18 @@ StackingContextHelper::StackingContextHe
                                              wr::DisplayListBuilder& aBuilder,
                                              WebRenderLayer* aLayer,
                                              const Maybe<gfx::Matrix4x4>& aTransform)
   : mBuilder(&aBuilder)
 {
   WrRect scBounds = aParentSC.ToRelativeWrRect(aLayer->BoundsForStackingContext());
   Layer* layer = aLayer->GetLayer();
   mTransform = aTransform.valueOr(layer->GetTransform());
-  mBuilder->PushStackingContext(scBounds,
-                                1.0f,
-                                mTransform,
+  float opacity = 1.0f;
+  mBuilder->PushStackingContext(scBounds, 0, &opacity, &mTransform,
                                 wr::ToWrMixBlendMode(layer->GetMixBlendMode()));
   mOrigin = aLayer->Bounds().TopLeft();
 }
 
 StackingContextHelper::StackingContextHelper(const StackingContextHelper& aParentSC,
                                              wr::DisplayListBuilder& aBuilder,
                                              WebRenderLayer* aLayer,
                                              uint64_t aAnimationsId,

--- a/gfx/webrender_bindings/WebRenderAPI.cpp
+++ b/gfx/webrender_bindings/WebRenderAPI.cpp
@@ -564,26 +564,16 @@ DisplayListBuilder::PushStackingContext(
   const WrMatrix* maybeTransform = aTransform ? &matrix : nullptr;
   WRDL_LOG("PushStackingContext b=%s t=%s\n", Stringify(aBounds).c_str(),
       aTransform ? Stringify(*aTransform).c_str() : "none");
   wr_dp_push_stacking_context(mWrState, aBounds, aAnimationId, aOpacity,
                               maybeTransform, aMixBlendMode);
 }
 
 void
-DisplayListBuilder::PushStackingContext(const WrRect& aBounds,
-                                        const float aOpacity,
-                                        const gfx::Matrix4x4& aTransform,
-                                        const WrMixBlendMode& aMixBlendMode)
-{
-  PushStackingContext(aBounds, 0, &aOpacity,
-                      &aTransform, aMixBlendMode);
-}
-
-void
 DisplayListBuilder::PopStackingContext()
 {
   WRDL_LOG("PopStackingContext\n");
   wr_dp_pop_stacking_context(mWrState);
 }
 
 void
 DisplayListBuilder::PushClip(const WrRect& aClipRect,

--- a/gfx/webrender_bindings/WebRenderAPI.h
+++ b/gfx/webrender_bindings/WebRenderAPI.h
@@ -140,21 +140,16 @@ public:
 
   void Begin(const LayerIntSize& aSize);
 
   void End();
   void Finalize(WrSize& aOutContentSize,
                 wr::BuiltDisplayList& aOutDisplayList);
 
   void PushStackingContext(const WrRect& aBounds, // TODO: We should work with strongly typed rects
-                           const float aOpacity,
-                           const gfx::Matrix4x4& aTransform,
-                           const WrMixBlendMode& aMixBlendMode);
-
-  void PushStackingContext(const WrRect& aBounds, // TODO: We should work with strongly typed rects
                            const uint64_t& aAnimationId,
                            const float* aOpacity,
                            const gfx::Matrix4x4* aTransform,
                            const WrMixBlendMode& aMixBlendMode);
   void PopStackingContext();
 
   void PushClip(const WrRect& aClipRect,
                 const WrImageMask* aMask);