This batch of changes upgrades Servo to work with the Rust upgrade as of

April 10, 2014. The main changes are to privacy, to work around the
issues with incorrect bounds on the libstd `Arc<Mutex<T>>`, and the
various API changes strewn throughout the libraries.

src/components/script/dom/bindings/callback.rs

@@ -8,8 +8,8 @@ use js::jsapi::{JS_GetProperty, JSTracer, JS_CallTracer};
 use js::jsval::{JSVal, UndefinedValue};
 use js::JSTRACE_OBJECT;
 
+use libc;
 use std::cast;
-use std::libc;
 use std::ptr;
 
 use serialize::{Encodable, Encoder};
@@ -27,11 +27,11 @@ pub enum ExceptionHandling {
 
 #[deriving(Clone,Eq)]
 pub struct CallbackInterface {
-    callback: *JSObject
+    pub callback: *JSObject
 }
 
-impl<S: Encoder> Encodable<S> for CallbackInterface {
-    fn encode(&self, s: &mut S) {
+impl<S: Encoder<E>, E> Encodable<S, E> for CallbackInterface {
+    fn encode(&self, s: &mut S) -> Result<(), E> {
         unsafe {
             let tracer: *mut JSTracer = cast::transmute(s);
             "callback".to_c_str().with_ref(|name| {
@@ -40,7 +40,8 @@ impl<S: Encoder> Encodable<S> for CallbackInterface {
                 (*tracer).debugPrintArg = name as *libc::c_void;
                 JS_CallTracer(tracer as *JSTracer, self.callback, JSTRACE_OBJECT as u32);
             });
-        }
+        };
+        Ok(())
     }
 }
 
@@ -98,8 +99,8 @@ pub fn WrapCallThisObject<T: 'static + CallbackContainer + Reflectable>(cx: *JSC
 }
 
 pub struct CallSetup {
-    cx: *JSContext,
-    handling: ExceptionHandling
+    pub cx: *JSContext,
+    pub handling: ExceptionHandling
 }
 
 impl CallSetup {