Avoid Clone for timer callbacks.

noclone.diff

diff --git a/components/script/timers.rs b/components/script/timers.rs
index a7395de..1d01c91 100644
--- a/components/script/timers.rs
+++ b/components/script/timers.rs
@@ -102,7 +102,7 @@ pub enum TimerCallback {
     FunctionTimerCallback(Rc<Function>),
 }

-#[derive(JSTraceable, Clone)]
+#[derive(JSTraceable)]
 enum InternalTimerCallback {
     StringTimerCallback(DOMString),
     FunctionTimerCallback(Rc<Function>, Rc<Vec<Heap<JSVal>>>),
@@ -227,33 +227,20 @@ impl ActiveTimers {

                 timers.pop().unwrap()
             };
-            let callback = timer.callback.clone();

             // prep for step 6 in nested set_timeout_or_interval calls
             self.nesting_level.set(timer.nesting_level);

-            // step 4.3
-            if timer.is_interval == IsInterval::Interval {
-                let mut timer = timer;
-
-                // step 7
-                timer.duration = self.clamp_duration(timer.duration);
-                // step 8, 9
-                timer.nesting_level += 1;
-                timer.next_call = base_time + timer.duration;
-                self.insert_timer(timer);
-            }
-
             // step 14
-            match callback {
-                InternalTimerCallback::StringTimerCallback(code_str) => {
+            match timer.callback {
+                InternalTimerCallback::StringTimerCallback(ref code_str) => {
                     let proxy = this.reflector().get_jsobject();
                     let cx = global_object_for_js_object(proxy.get()).r().get_cx();
                     let mut rval = RootedValue::new(cx, UndefinedValue());

-                    this.evaluate_js_on_global_with_result(&code_str, rval.handle_mut());
+                    this.evaluate_js_on_global_with_result(code_str, rval.handle_mut());
                 },
-                InternalTimerCallback::FunctionTimerCallback(function, arguments) => {
+                InternalTimerCallback::FunctionTimerCallback(ref function, ref arguments) => {
                     let arguments: Vec<JSVal> = arguments.iter().map(|arg| arg.get()).collect();
                     let arguments = arguments.iter().by_ref().map(|arg| unsafe {
                         HandleValue::from_marked_location(arg)
@@ -263,6 +250,18 @@ impl ActiveTimers {
                 }
             };

+            // step 4.3
+            if timer.is_interval == IsInterval::Interval {
+                let mut timer = timer;
+
+                // step 7
+                timer.duration = self.clamp_duration(timer.duration);
+                // step 8, 9
+                timer.nesting_level += 1;
+                timer.next_call = base_time + timer.duration;
+                self.insert_timer(timer);
+            }
+
             self.nesting_level.set(0);
         }