Fix some "unnecessary parentheses" warnings

3 files changed, 4 insertions, 4 deletions

diff --git a/components/script/dom/cssrulelist.rs b/components/script/dom/cssrulelist.rs
index 1f800a6a0b4..baa685d5a72 100644
--- a/components/script/dom/cssrulelist.rs
+++ b/components/script/dom/cssrulelist.rs
@@ -103,7 +103,7 @@ impl CSSRuleList {
         let parent_stylesheet = &*self.parent_stylesheet;
         let dom_rule = CSSRule::new_specific(&window, parent_stylesheet, new_rule);
         self.dom_rules.borrow_mut().insert(index, MutNullableDom::new(Some(&*dom_rule)));
-        Ok((idx))
+        Ok(idx)
     }
 
     // In case of a keyframe rule, index must be valid.
diff --git a/components/script/dom/performanceobserver.rs b/components/script/dom/performanceobserver.rs
index 96ad99edf92..af43fe76246 100644
--- a/components/script/dom/performanceobserver.rs
+++ b/components/script/dom/performanceobserver.rs
@@ -106,7 +106,7 @@ impl PerformanceObserverMethods for PerformanceObserver {
         // step 2
         // There must be at least one valid entry type.
         if entry_types.is_empty() {
-            return Err((Error::Type("entryTypes cannot be empty".to_string())));
+            return Err(Error::Type("entryTypes cannot be empty".to_string()));
         }
 
         // step 3-4-5
diff --git a/components/script/dom/screen.rs b/components/script/dom/screen.rs
index bec082e9729..3cd54034994 100644
--- a/components/script/dom/screen.rs
+++ b/components/script/dom/screen.rs
@@ -39,14 +39,14 @@ impl Screen {
         let (send, recv) = ipc::channel::<(Size2D<u32>)>().unwrap();
         self.window.upcast::<GlobalScope>()
             .script_to_constellation_chan().send(ScriptMsg::GetScreenSize(send)).unwrap();
-        recv.recv().unwrap_or((Size2D::zero()))
+        recv.recv().unwrap_or(Size2D::zero())
     }
 
     fn screen_avail_size(&self) -> Size2D<u32> {
         let (send, recv) = ipc::channel::<(Size2D<u32>)>().unwrap();
         self.window.upcast::<GlobalScope>()
             .script_to_constellation_chan().send(ScriptMsg::GetScreenAvailSize(send)).unwrap();
-        recv.recv().unwrap_or((Size2D::zero()))
+        recv.recv().unwrap_or(Size2D::zero())
     }
 }