diff --git a/gfx/wr/webrender/src/prim_store/image.rs b/gfx/wr/webrender/src/prim_store/image.rs
index bd72572540ce..922bd5b80cd9 100644
--- a/gfx/wr/webrender/src/prim_store/image.rs
+++ b/gfx/wr/webrender/src/prim_store/image.rs
@@ -76,7 +76,6 @@ pub struct Image {
     pub stretch_size: SizeKey,
     pub tile_spacing: SizeKey,
     pub color: ColorU,
-    pub sub_rect: Option<DeviceIntRect>,
     pub image_rendering: ImageRendering,
     pub alpha_type: AlphaType,
 }
@@ -122,7 +121,6 @@ pub struct ImageData {
     pub color: ColorF,
     pub source: ImageSource,
     pub image_rendering: ImageRendering,
-    pub sub_rect: Option<DeviceIntRect>,
     pub alpha_type: AlphaType,
 }
 
@@ -134,7 +132,6 @@ impl From<Image> for ImageData {
             stretch_size: image.stretch_size.into(),
             tile_spacing: image.tile_spacing.into(),
             source: ImageSource::Default,
-            sub_rect: image.sub_rect,
             image_rendering: image.image_rendering,
             alpha_type: image.alpha_type,
         }
@@ -172,18 +169,6 @@ impl ImageData {
                         };
                     }
 
-                    // Work out whether this image is a normal / simple type, or if
-                    // we need to pre-render it to the render task cache.
-                    if let Some(rect) = self.sub_rect {
-                        // We don't properly support this right now.
-                        debug_assert!(!is_tiled);
-                        self.source = ImageSource::Cache {
-                            // Size in device-pixels we need to allocate in render task cache.
-                            size: rect.size,
-                            handle: None,
-                        };
-                    }
-
                     let mut is_opaque = image_properties.descriptor.is_opaque();
                     let request = ImageRequest {
                         key: self.key,
@@ -211,7 +196,7 @@ impl ImageData {
 
                             let image_cache_key = ImageCacheKey {
                                 request,
-                                texel_rect: self.sub_rect,
+                                texel_rect: None,
                             };
                             let target_kind = if image_properties.descriptor.format.bytes_per_pixel() == 1 {
                                 RenderTargetKind::Alpha
@@ -343,7 +328,6 @@ impl CreateShadow for Image {
             tile_spacing: self.tile_spacing,
             stretch_size: self.stretch_size,
             key: self.key,
-            sub_rect: self.sub_rect,
             image_rendering: self.image_rendering,
             alpha_type: self.alpha_type,
             color: shadow.color.into(),
@@ -518,9 +502,9 @@ fn test_struct_sizes() {
     //     test expectations and move on.
     // (b) You made a structure larger. This is not necessarily a problem, but should only
     //     be done with care, and after checking if talos performance regresses badly.
-    assert_eq!(mem::size_of::<Image>(), 52, "Image size changed");
-    assert_eq!(mem::size_of::<ImageTemplate>(), 112, "ImageTemplate size changed");
-    assert_eq!(mem::size_of::<ImageKey>(), 72, "ImageKey size changed");
+    assert_eq!(mem::size_of::<Image>(), 32, "Image size changed");
+    assert_eq!(mem::size_of::<ImageTemplate>(), 92, "ImageTemplate size changed");
+    assert_eq!(mem::size_of::<ImageKey>(), 52, "ImageKey size changed");
     assert_eq!(mem::size_of::<YuvImage>(), 32, "YuvImage size changed");
     assert_eq!(mem::size_of::<YuvImageTemplate>(), 60, "YuvImageTemplate size changed");
     assert_eq!(mem::size_of::<YuvImageKey>(), 52, "YuvImageKey size changed");
diff --git a/gfx/wr/webrender/src/scene_building.rs b/gfx/wr/webrender/src/scene_building.rs
index 8e39af6c21cf..be03baee65bb 100644
--- a/gfx/wr/webrender/src/scene_building.rs
+++ b/gfx/wr/webrender/src/scene_building.rs
@@ -955,7 +955,6 @@ impl<'a> SceneBuilder<'a> {
                     &layout,
                     layout.rect.size,
                     LayoutSize::zero(),
-                    None,
                     info.image_key,
                     info.image_rendering,
                     info.alpha_type,
@@ -980,7 +979,6 @@ impl<'a> SceneBuilder<'a> {
                     &layout,
                     stretch_size,
                     info.tile_spacing,
-                    None,
                     info.image_key,
                     info.image_rendering,
                     info.alpha_type,
@@ -3098,7 +3096,6 @@ impl<'a> SceneBuilder<'a> {
         info: &LayoutPrimitiveInfo,
         stretch_size: LayoutSize,
         mut tile_spacing: LayoutSize,
-        sub_rect: Option<TexelRect>,
         image_key: ImageKey,
         image_rendering: ImageRendering,
         alpha_type: AlphaType,
@@ -3111,19 +3108,6 @@ impl<'a> SceneBuilder<'a> {
             .. *info
         };
 
-        let sub_rect = sub_rect.map(|texel_rect| {
-            DeviceIntRect::new(
-                DeviceIntPoint::new(
-                    texel_rect.uv0.x as i32,
-                    texel_rect.uv0.y as i32,
-                ),
-                DeviceIntSize::new(
-                    (texel_rect.uv1.x - texel_rect.uv0.x) as i32,
-                    (texel_rect.uv1.y - texel_rect.uv0.y) as i32,
-                ),
-            )
-        });
-
         self.add_primitive(
             spatial_node_index,
             clip_chain_id,
@@ -3134,7 +3118,6 @@ impl<'a> SceneBuilder<'a> {
                 tile_spacing: tile_spacing.into(),
                 stretch_size: stretch_size.into(),
                 color: color.into(),
-                sub_rect,
                 image_rendering,
                 alpha_type,
             },