Run rustfmt on selectors, servo_arc, and style.

This was generated with:

./mach cargo fmt --package selectors &&
./mach cargo fmt --package servo_arc &&
./mach cargo fmt --package style

Using rustfmt 0.4.1-nightly (a4462d1 2018-03-26)

components/style/sharing/checks.rs

@@ -16,7 +16,7 @@ use sharing::{StyleSharingCandidate, StyleSharingTarget};
 /// sharing.
 pub fn parents_allow_sharing<E>(
     target: &mut StyleSharingTarget<E>,
-    candidate: &mut StyleSharingCandidate<E>
+    candidate: &mut StyleSharingCandidate<E>,
 ) -> bool
 where
     E: TElement,
@@ -58,7 +58,7 @@ where
 /// Whether two elements have the same same style attribute (by pointer identity).
 pub fn have_same_style_attribute<E>(
     target: &mut StyleSharingTarget<E>,
-    candidate: &mut StyleSharingCandidate<E>
+    candidate: &mut StyleSharingCandidate<E>,
 ) -> bool
 where
     E: TElement,
@@ -66,14 +66,14 @@ where
     match (target.style_attribute(), candidate.style_attribute()) {
         (None, None) => true,
         (Some(_), None) | (None, Some(_)) => false,
-        (Some(a), Some(b)) => &*a as *const _ == &*b as *const _
+        (Some(a), Some(b)) => &*a as *const _ == &*b as *const _,
     }
 }
 
 /// Whether two elements have the same same presentational attributes.
 pub fn have_same_presentational_hints<E>(
     target: &mut StyleSharingTarget<E>,
-    candidate: &mut StyleSharingCandidate<E>
+    candidate: &mut StyleSharingCandidate<E>,
 ) -> bool
 where
     E: TElement,
@@ -114,18 +114,10 @@ where
 {
     let stylist = &shared_context.stylist;
 
-    let for_element = target.revalidation_match_results(
-        stylist,
-        bloom,
-        nth_index_cache,
-        selector_flags_map,
-    );
+    let for_element =
+        target.revalidation_match_results(stylist, bloom, nth_index_cache, selector_flags_map);
 
-    let for_candidate = candidate.revalidation_match_results(
-        stylist,
-        bloom,
-        nth_index_cache,
-    );
+    let for_candidate = candidate.revalidation_match_results(stylist, bloom, nth_index_cache);
 
     // This assert "ensures", to some extent, that the two candidates have
     // matched the same rulehash buckets, and as such, that the bits we're
@@ -156,7 +148,7 @@ where
 
     let may_have_rules_for_element = match element_id {
         Some(id) => stylist.may_have_rules_for_id(id, element),
-        None => false
+        None => false,
     };
 
     if may_have_rules_for_element {
@@ -165,6 +157,6 @@ where
 
     match candidate_id {
         Some(id) => stylist.may_have_rules_for_id(id, candidate),
-        None => false
+        None => false,
     }
 }