Make use of RefCell::try_borrow_unguarded

components/constellation/constellation.rs

@@ -2030,6 +2030,10 @@ where
             None
         };
 
+        // https://github.com/rust-lang/rust/issues/59159
+        let browsing_context_size = browsing_context.size;
+        let browsing_context_is_visible = browsing_context.is_visible;
+
         // Create the new pipeline, attached to the parent and push to pending changes
         self.new_pipeline(
             new_pipeline_id,
@@ -2037,11 +2041,11 @@ where
             top_level_browsing_context_id,
             Some(parent_pipeline_id),
             None,
-            browsing_context.size,
+            browsing_context_size,
             load_data,
             load_info.sandbox,
             is_private,
-            browsing_context.is_visible,
+            browsing_context_is_visible,
         );
         self.add_pending_change(SessionHistoryChange {
             top_level_browsing_context_id: top_level_browsing_context_id,

components/script/dom/bindings/cell.rs

@@ -26,7 +26,9 @@ impl<T> DomRefCell<T> {
     #[allow(unsafe_code)]
     pub unsafe fn borrow_for_layout(&self) -> &T {
         debug_assert!(thread_state::get().is_layout());
-        &*self.value.as_ptr()
+        self.value
+            .try_borrow_unguarded()
+            .expect("cell is mutably borrowed")
     }
 
     /// Borrow the contents for the purpose of script deallocation.

components/script/dom/xmlhttprequest.rs

@@ -1442,8 +1442,6 @@ impl XMLHttpRequest {
 
     fn filter_response_headers(&self) -> HeaderMap {
         // https://fetch.spec.whatwg.org/#concept-response-header-list
-        use http::header::{self, HeaderName};
-
         let mut headers = self.response_headers.borrow().clone();
         headers.remove(header::SET_COOKIE);
         headers.remove(HeaderName::from_static("set-cookie2"));

components/script/lib.rs

@@ -4,6 +4,7 @@
 
 #![cfg_attr(feature = "unstable", feature(core_intrinsics))]
 #![cfg_attr(feature = "unstable", feature(on_unimplemented))]
+#![feature(borrow_state)]
 #![feature(const_fn)]
 #![feature(drain_filter)]
 #![feature(inner_deref)]

components/style/error_reporting.rs

@@ -245,7 +245,6 @@ impl ParseErrorReporter for RustLogReporter {
         location: SourceLocation,
         error: ContextualParseError,
     ) {
-        use log;
         if log_enabled!(log::Level::Info) {
             info!(
                 "Url:\t{}\n{}:{} {}",

components/style/servo/selector_parser.rs

@@ -354,7 +354,6 @@ impl NonTSPseudoClass {
     /// selector matching, and it's set from the DOM.
     pub fn state_flag(&self) -> ElementState {
         use self::NonTSPseudoClass::*;
-        use crate::element_state::ElementState;
         match *self {
             Active => ElementState::IN_ACTIVE_STATE,
             Focus => ElementState::IN_FOCUS_STATE,

rust-toolchain

@@ -1 +1 @@
-nightly-2019-03-26
+nightly-2019-04-12