clippy:fix various clippy problems in components/scripts

components/script/dom/characterdata.rs

@@ -136,7 +136,7 @@ impl CharacterDataMethods for CharacterData {
                 // and then transcoded that to UTF-8 lossily,
                 // since our DOMString is currently strict UTF-8.
                 if astral.is_some() {
-                    substring = substring + "\u{FFFD}";
+                    substring += "\u{FFFD}";
                 }
                 remaining = s;
             },
@@ -145,15 +145,15 @@ impl CharacterDataMethods for CharacterData {
         }
         match split_at_utf16_code_unit_offset(remaining, count, replace_surrogates) {
             // Steps 3.
-            Err(()) => substring = substring + remaining,
+            Err(()) => substring += remaining,
             // Steps 4.
             Ok((s, astral, _)) => {
                 substring = substring + s;
                 // As if we had split the UTF-16 surrogate pair in half
                 // and then transcoded that to UTF-8 lossily,
                 // since our DOMString is currently strict UTF-8.
                 if astral.is_some() {
-                    substring = substring + "\u{FFFD}";
+                    substring += "\u{FFFD}";
                 }
             },
         };

components/script/dom/console.rs

@@ -90,7 +90,7 @@ fn stringify_handle_value(message: HandleValue) -> DOMString {
         ) -> DOMString {
             rooted!(in(cx) let mut obj = value.to_object());
             let mut object_class = ESClass::Other;
-            if !GetBuiltinClass(cx, obj.handle().into(), &mut object_class as *mut _) {
+            if !GetBuiltinClass(cx, obj.handle(), &mut object_class as *mut _) {
                 return DOMString::from("/* invalid */");
             }
             let mut ids = IdVector::new(cx);
@@ -120,9 +120,9 @@ fn stringify_handle_value(message: HandleValue) -> DOMString {
                 let mut is_none = false;
                 if !JS_GetOwnPropertyDescriptorById(
                     cx,
-                    obj.handle().into(),
-                    id.handle().into(),
-                    desc.handle_mut().into(),
+                    obj.handle(),
+                    id.handle(),
+                    desc.handle_mut(),
                     &mut is_none,
                 ) {
                     return DOMString::from("/* invalid */");
@@ -191,7 +191,7 @@ fn stringify_handle_value(message: HandleValue) -> DOMString {
             parents.push(value_bits);
             stringify_object_from_handle_value(cx, value, parents)
         }
-        stringify_inner(cx, message.into(), Vec::new())
+        stringify_inner(cx, message, Vec::new())
     }
 }
 

components/script/dom/cssstyledeclaration.rs

@@ -361,8 +361,8 @@ lazy_static! {
         enabled_longhands.sort_unstable_by(|a, b| {
             let a = a.name();
             let b = b.name();
-            let is_a_vendor_prefixed = a.starts_with("-");
-            let is_b_vendor_prefixed = b.starts_with("-");
+            let is_a_vendor_prefixed = a.starts_with('-');
+            let is_b_vendor_prefixed = b.starts_with('-');
             if is_a_vendor_prefixed == is_b_vendor_prefixed {
                 a.partial_cmp(b).unwrap()
             } else if is_b_vendor_prefixed {

components/script/dom/customelementregistry.rs

@@ -290,7 +290,7 @@ impl CustomElementRegistryMethods for CustomElementRegistry {
             .definitions
             .borrow()
             .iter()
-            .any(|(_, ref def)| def.constructor == constructor_)
+            .any(|(_, def)| def.constructor == constructor_)
         {
             return Err(Error::NotSupported);
         }
@@ -1035,7 +1035,7 @@ pub fn is_valid_custom_element_name(name: &str) -> bool {
     // PotentialCustomElementName ::= [a-z] (PCENChar)* '-' (PCENChar)*
 
     let mut chars = name.chars();
-    if !chars.next().map_or(false, |c| ('a'..='z').contains(&c)) {
+    if !chars.next().map_or(false, |c| c.is_ascii_lowercase()) {
         return false;
     }
 
@@ -1078,8 +1078,8 @@ fn is_potential_custom_element_char(c: char) -> bool {
         c == '.' ||
         c == '_' ||
         c == '\u{B7}' ||
-        ('0'..='9').contains(&c) ||
-        ('a'..='z').contains(&c) ||
+        c.is_ascii_digit() ||
+        c.is_ascii_lowercase() ||
         ('\u{C0}'..='\u{D6}').contains(&c) ||
         ('\u{D8}'..='\u{F6}').contains(&c) ||
         ('\u{F8}'..='\u{37D}').contains(&c) ||