Replaced DOMString constructor by conversion functions.

Replaced DOMString(...) by DOMString::from(...).
Replaced ....0 by String::from(...).
Removed any uses of .to_owner() in DOMString::from("...").

components/script/dom/textencoder.rs

@@ -66,7 +66,7 @@ impl TextEncoder {
 impl TextEncoderMethods for TextEncoder {
     // https://encoding.spec.whatwg.org/#dom-textencoder-encoding
     fn Encoding(&self) -> DOMString {
-        DOMString(self.encoder.name().to_owned())
+        DOMString::from(self.encoder.name())
     }
 
     #[allow(unsafe_code)]