Make style context use parking_lot::RwLock

components/style/animation.rs

@@ -672,7 +672,7 @@ pub fn complete_expired_transitions(node: OpaqueNode, style: &mut Arc<ComputedVa
                                     context: &SharedStyleContext) -> bool {
     let had_animations_to_expire;
     {
-        let all_expired_animations = context.expired_animations.read().unwrap();
+        let all_expired_animations = context.expired_animations.read();
         let animations_to_expire = all_expired_animations.get(&node);
         had_animations_to_expire = animations_to_expire.is_some();
         if let Some(ref animations) = animations_to_expire {
@@ -686,7 +686,7 @@ pub fn complete_expired_transitions(node: OpaqueNode, style: &mut Arc<ComputedVa
     }
 
     if had_animations_to_expire {
-        context.expired_animations.write().unwrap().remove(&node);
+        context.expired_animations.write().remove(&node);
     }
 
     had_animations_to_expire

components/style/context.rs

@@ -10,10 +10,11 @@ use dom::OpaqueNode;
 use error_reporting::ParseErrorReporter;
 use euclid::Size2D;
 use matching::{ApplicableDeclarationsCache, StyleSharingCandidateCache};
+use parking_lot::RwLock;
 use selector_matching::Stylist;
 use std::cell::RefCell;
 use std::collections::HashMap;
-use std::sync::{Arc, Mutex, RwLock};
+use std::sync::{Arc, Mutex};
 use std::sync::mpsc::Sender;
 use timer::Timer;
 

components/style/gecko/data.rs

@@ -12,11 +12,12 @@ use gecko_bindings::sugar::ownership::{HasBoxFFI, HasFFI, HasSimpleFFI};
 use media_queries::{Device, MediaType};
 use num_cpus;
 use parallel::WorkQueueData;
+use parking_lot::RwLock;
 use selector_matching::Stylist;
 use std::cmp;
 use std::collections::HashMap;
 use std::env;
-use std::sync::{Arc, RwLock};
+use std::sync::Arc;
 use std::sync::mpsc::{Receiver, Sender, channel};
 use style_traits::ViewportPx;
 use stylesheets::Stylesheet;

components/style/matching.rs

@@ -605,11 +605,10 @@ trait PrivateMatchMethods: TElement {
         // Merge any running transitions into the current style, and cancel them.
         let had_running_animations = context.running_animations
                                             .read()
-                                            .unwrap()
                                             .get(&this_opaque)
                                             .is_some();
         if had_running_animations {
-            let mut all_running_animations = context.running_animations.write().unwrap();
+            let mut all_running_animations = context.running_animations.write();
             for mut running_animation in all_running_animations.get_mut(&this_opaque).unwrap() {
                 // This shouldn't happen frequently, but under some
                 // circumstances mainly huge load or debug builds, the