Don't force reflow on content changes

This fixes a performance regression caused by the previous patches.  Once we
allowed script and layout to run during parsing, it was running too often
(every time the document changed and called window.reflow).

Fixes #1269.

components/script/dom/window.rs

@@ -19,7 +19,7 @@ use dom::location::Location;
 use dom::navigator::Navigator;
 use dom::performance::Performance;
 use dom::screen::Screen;
-use layout_interface::{ReflowGoal, ReflowForDisplay};
+use layout_interface::ReflowGoal;
 use page::Page;
 use script_task::{ExitWindowMsg, ScriptChan, TriggerLoadMsg, TriggerFragmentMsg};
 use script_task::FromWindow;
@@ -348,10 +348,6 @@ impl<'a> WindowHelpers for JSRef<'a, Window> {
 
     fn reflow(self) {
         self.page().damage();
-        // FIXME This should probably be ReflowForQuery, not Display. All queries currently
-        // currently rely on the display list, which means we can't destroy it by
-        // doing a query reflow.
-        self.page().reflow(ReflowForDisplay, self.control_chan.clone(), &*self.compositor);
     }
 
     fn flush_layout(self, goal: ReflowGoal) {