script: Address review comments

components/script/dom/document.rs

@@ -372,7 +372,7 @@ impl<'a> DocumentHelpers<'a> for JSRef<'a, Document> {
     /// page content during parsing.
     fn set_reflow_timeout(self, timeout: u64) {
         if let Some(existing_timeout) = self.reflow_timeout.get() {
-            if existing_timeout > timeout {
+            if existing_timeout < timeout {
                 return
             }
         }

components/script/dom/htmlbodyelement.rs

@@ -100,6 +100,10 @@ impl<'a> VirtualMethods for JSRef<'a, HTMLBodyElement> {
             s.bind_to_tree(tree_in_doc);
         }
 
+        if !tree_in_doc {
+            return
+        }
+
         let window = window_from_node(*self).root();
         let document = window.r().Document().root();
         document.r().set_reflow_timeout(time::precise_time_ns() + INITIAL_REFLOW_DELAY);

components/script/dom/servohtmlparser.rs

@@ -303,10 +303,8 @@ impl<'a> PrivateServoHTMLParserHelpers for JSRef<'a, ServoHTMLParser> {
                 break;
             }
 
-            {
-                let document = self.document.root();
-                document.r().reflow_if_reflow_timer_expired();
-            }
+            let document = self.document.root();
+            document.r().reflow_if_reflow_timer_expired();
 
             let mut pending_input = self.pending_input.borrow_mut();
             if !pending_input.is_empty() {