Add methods to move ByteStrings underlying bytes

Add methods to move the underlying Vec<u8> for ByteString.

components/script/dom/bindings/str.rs

@@ -7,6 +7,7 @@
 use std::ascii::AsciiExt;
 use std::borrow::ToOwned;
 use std::hash::{Hash, Hasher};
+use std::mem;
 use std::ops;
 use std::str;
 use std::str::FromStr;
@@ -28,6 +29,12 @@ impl ByteString {
         str::from_utf8(&vec).ok()
     }
 
+    /// Returns ownership of the underlying Vec<u8> and copies an empty
+    /// vec in its place
+    pub fn bytes(&mut self) -> Vec<u8> {
+        mem::replace(&mut self.0, Vec::new())
+    }
+
     /// Returns the length.
     pub fn len(&self) -> usize {
         let ByteString(ref vector) = *self;
@@ -117,6 +124,12 @@ impl ByteString {
     }
 }
 
+impl Into<Vec<u8>> for ByteString {
+    fn into(self) -> Vec<u8> {
+        self.0
+    }
+}
+
 impl Hash for ByteString {
     fn hash<H: Hasher>(&self, state: &mut H) {
         let ByteString(ref vec) = *self;

components/script/dom/xmlhttprequest.rs

@@ -435,7 +435,7 @@ impl XMLHttpRequestMethods for XMLHttpRequest {
             None => {}
         }
 
-        headers.set_raw(name_str.to_owned(), vec![value.to_vec()]);
+        headers.set_raw(name_str.to_owned(), vec![value.into()]);
         Ok(())
     }
 

tests/unit/script/dom/bindings.rs

@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use script::dom::bindings::str::ByteString;
+
+#[test]
+fn test_byte_string_move() {
+    let mut byte_str = ByteString::new(vec![0x73, 0x65, 0x72, 0x76, 0x6f]);
+    let mut byte_vec = byte_str.bytes();
+
+    assert_eq!(byte_vec, "servo".as_bytes());
+    assert_eq!(*byte_str, []);
+
+    byte_vec = byte_str.into();
+    assert_eq!(byte_vec, Vec::new());
+}

tests/unit/script/lib.rs

@@ -9,5 +9,6 @@ extern crate util;
 #[cfg(all(test, target_pointer_width = "64"))] mod size_of;
 #[cfg(test)] mod textinput;
 #[cfg(test)] mod dom {
+    mod bindings;
     mod blob;
 }