Use mitochondria

Cargo.lock

@@ -2749,9 +2749,9 @@ dependencies = [
  "gfx_traits",
  "ipc-channel",
  "libc",
+ "mitochondria",
  "msg",
  "net_traits",
- "once_cell",
  "parking_lot",
  "range",
  "rayon",
@@ -3710,12 +3710,6 @@ dependencies = [
  "objc",
 ]
 
-[[package]]
-name = "once_cell"
-version = "1.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "891f486f630e5c5a4916c7e16c4b24a53e78c860b646e9f8e005e4f16847bfed"
-
 [[package]]
 name = "opaque-debug"
 version = "0.2.1"

components/layout_2020/Cargo.toml

@@ -24,8 +24,8 @@ gfx_traits = {path = "../gfx_traits"}
 ipc-channel = "0.12"
 libc = "0.2"
 msg = {path = "../msg"}
+mitochondria = "1.1.2"
 net_traits = {path = "../net_traits"}
-once_cell = "1.2.0"
 parking_lot = "0.9"
 range = {path = "../range"}
 rayon = "1"

components/layout_2020/display_list.rs

@@ -9,8 +9,8 @@ use crate::replaced::IntrinsicSizes;
 use embedder_traits::Cursor;
 use euclid::{Point2D, SideOffsets2D, Size2D, Vector2D};
 use gfx::text::glyph::GlyphStore;
+use mitochondria::OnceCell;
 use net_traits::image_cache::UsePlaceholder;
-use once_cell::unsync::OnceCell;
 use std::sync::Arc;
 use style::dom::OpaqueNode;
 use style::properties::ComputedValues;
@@ -175,7 +175,7 @@ impl<'a> BuilderForBoxFragment<'a> {
     }
 
     fn content_rect(&self) -> &units::LayoutRect {
-        self.content_rect.get_or_init(|| {
+        self.content_rect.init_once(|| {
             self.fragment
                 .content_rect
                 .to_physical(self.fragment.style.writing_mode, self.containing_block)
@@ -185,7 +185,7 @@ impl<'a> BuilderForBoxFragment<'a> {
     }
 
     fn padding_rect(&self) -> &units::LayoutRect {
-        self.padding_rect.get_or_init(|| {
+        self.padding_rect.init_once(|| {
             self.fragment
                 .padding_rect()
                 .to_physical(self.fragment.style.writing_mode, self.containing_block)
@@ -199,7 +199,7 @@ impl<'a> BuilderForBoxFragment<'a> {
         builder: &mut DisplayListBuilder,
         common: &mut wr::CommonItemProperties,
     ) {
-        let initialized = self.border_edge_clip_id.get_or_init(|| {
+        let initialized = self.border_edge_clip_id.init_once(|| {
             if self.border_radius.is_zero() {
                 None
             } else {