Auto merge of #21325 - gterzian:crossbeam_integration, r=SimonSapin,jdm

Replace mpsc with crossbeam-channel

Follow up on https://github.com/servo/servo/pull/19515

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Selecting over multiple channels in `std::sync::mpsc` is not stable and likely never will be:

https://github.com/rust-lang/rust/issues/27800#issuecomment-260136777
> It seems the only thing keeping `mpsc_select` around is Servo.

crossbeam-channel is designed specifically to replace `std::sync::mpsc` and fix many of its shortcomings:
https://github.com/stjepang/rfcs-crossbeam/blob/channel/text/2017-11-09-channel.md

This is to be landed together with https://github.com/servo/ipc-channel/pull/183.

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1 files changed, 2 insertions, 2 deletions

diff --git a/components/layout/animation.rs b/components/layout/animation.rs
index d8b305644c0..b42933bb400 100644
--- a/components/layout/animation.rs
+++ b/components/layout/animation.rs
@@ -13,7 +13,7 @@ use msg::constellation_msg::PipelineId;
 use opaque_node::OpaqueNodeMethods;
 use script_traits::{AnimationState, ConstellationControlMsg, LayoutMsg as ConstellationMsg};
 use script_traits::UntrustedNodeAddress;
-use std::sync::mpsc::Receiver;
+use servo_channel::Receiver;
 use style::animation::{Animation, update_style_for_animation};
 use style::dom::TElement;
 use style::font_metrics::ServoMetricsProvider;
@@ -36,7 +36,7 @@ pub fn update_animation_state<E>(
     E: TElement,
 {
     let mut new_running_animations = vec![];
-    while let Ok(animation) = new_animations_receiver.try_recv() {
+    while let Some(animation) = new_animations_receiver.try_recv() {
         let mut should_push = true;
         if let Animation::Keyframes(ref node, _, ref name, ref state) = animation {
             // If the animation was already present in the list for the