diff --git a/gfx/gl/SharedSurfaceIO.cpp b/gfx/gl/SharedSurfaceIO.cpp
index 00567e2b3aec..d1ab389f7360 100644
--- a/gfx/gl/SharedSurfaceIO.cpp
+++ b/gfx/gl/SharedSurfaceIO.cpp
@@ -92,8 +92,7 @@ Maybe<layers::SurfaceDescriptor>
 SharedSurface_IOSurface::ToSurfaceDescriptor() {
   const bool isOpaque = false;  // RGBA
   return Some(layers::SurfaceDescriptorMacIOSurface(
-      mIOSurf->GetIOSurfaceID(), mIOSurf->GetContentsScaleFactor(), isOpaque,
-      mIOSurf->GetYUVColorSpace()));
+      mIOSurf->GetIOSurfaceID(), isOpaque, mIOSurf->GetYUVColorSpace()));
 }
 
 }  // namespace gl
diff --git a/gfx/layers/ipc/LayersSurfaces.ipdlh b/gfx/layers/ipc/LayersSurfaces.ipdlh
index e95afae5e2dc..7e59365c8f95 100644
--- a/gfx/layers/ipc/LayersSurfaces.ipdlh
+++ b/gfx/layers/ipc/LayersSurfaces.ipdlh
@@ -56,7 +56,6 @@ namespace layers {
 
 [Comparable] struct SurfaceDescriptorMacIOSurface {
   uint32_t surfaceId;
-  double scaleFactor;
   bool isOpaque;
   YUVColorSpace yUVColorSpace;
 };
diff --git a/gfx/layers/opengl/MacIOSurfaceTextureClientOGL.cpp b/gfx/layers/opengl/MacIOSurfaceTextureClientOGL.cpp
index 4b98c54def51..026814d02b93 100644
--- a/gfx/layers/opengl/MacIOSurfaceTextureClientOGL.cpp
+++ b/gfx/layers/opengl/MacIOSurfaceTextureClientOGL.cpp
@@ -50,17 +50,17 @@ MacIOSurfaceTextureData* MacIOSurfaceTextureData::Create(const IntSize& aSize,
 }
 
 bool MacIOSurfaceTextureData::Serialize(SurfaceDescriptor& aOutDescriptor) {
-  aOutDescriptor = SurfaceDescriptorMacIOSurface(
-      mSurface->GetIOSurfaceID(), mSurface->GetContentsScaleFactor(),
-      !mSurface->HasAlpha(), mSurface->GetYUVColorSpace());
+  aOutDescriptor = SurfaceDescriptorMacIOSurface(mSurface->GetIOSurfaceID(),
+                                                 !mSurface->HasAlpha(),
+                                                 mSurface->GetYUVColorSpace());
   return true;
 }
 
 void MacIOSurfaceTextureData::GetSubDescriptor(
     RemoteDecoderVideoSubDescriptor* const aOutDesc) {
-  *aOutDesc = SurfaceDescriptorMacIOSurface(
-      mSurface->GetIOSurfaceID(), mSurface->GetContentsScaleFactor(),
-      !mSurface->HasAlpha(), mSurface->GetYUVColorSpace());
+  *aOutDesc = SurfaceDescriptorMacIOSurface(mSurface->GetIOSurfaceID(),
+                                            !mSurface->HasAlpha(),
+                                            mSurface->GetYUVColorSpace());
 }
 
 void MacIOSurfaceTextureData::FillInfo(TextureData::Info& aInfo) const {
diff --git a/gfx/layers/opengl/MacIOSurfaceTextureHostOGL.cpp b/gfx/layers/opengl/MacIOSurfaceTextureHostOGL.cpp
index 9690e10db10b..65c43c135172 100644
--- a/gfx/layers/opengl/MacIOSurfaceTextureHostOGL.cpp
+++ b/gfx/layers/opengl/MacIOSurfaceTextureHostOGL.cpp
@@ -19,9 +19,9 @@ MacIOSurfaceTextureHostOGL::MacIOSurfaceTextureHostOGL(
     TextureFlags aFlags, const SurfaceDescriptorMacIOSurface& aDescriptor)
     : TextureHost(aFlags) {
   MOZ_COUNT_CTOR(MacIOSurfaceTextureHostOGL);
-  mSurface = MacIOSurface::LookupSurface(
-      aDescriptor.surfaceId(), aDescriptor.scaleFactor(),
-      !aDescriptor.isOpaque(), aDescriptor.yUVColorSpace());
+  mSurface = MacIOSurface::LookupSurface(aDescriptor.surfaceId(),
+                                         !aDescriptor.isOpaque(),
+                                         aDescriptor.yUVColorSpace());
   if (!mSurface) {
     gfxCriticalNote << "Failed to look up MacIOSurface";
   }