"javascript:" urls: clean up js evaluation code

- move it to its own function
- move the `url = "about:blank" code into the same block
- move the `use` statement to the top of the file

components/script/script_thread.rs

@@ -119,6 +119,7 @@ use task_source::performance_timeline::{PerformanceTimelineTask, PerformanceTime
 use task_source::user_interaction::{UserInteractionTask, UserInteractionTaskSource};
 use time::{get_time, precise_time_ns, Tm};
 use url::Position;
+use url::percent_encoding::percent_decode;
 use webdriver_handlers;
 use webvr_traits::{WebVREvent, WebVRMsg};
 
@@ -2309,20 +2310,28 @@ impl ScriptThread {
                               browsing_context_id: Option<BrowsingContextId>,
                               mut load_data: LoadData,
                               replace: bool) {
+        let is_javascript = load_data.url.scheme() == "javascript";
+        if is_javascript {
+            self.eval_js_url(parent_pipeline_id, &mut load_data);
+        }
+
         match browsing_context_id {
             Some(browsing_context_id) => {
                 let iframe = self.documents.borrow().find_iframe(parent_pipeline_id, browsing_context_id);
                 if let Some(iframe) = iframe {
                     iframe.navigate_or_reload_child_browsing_context(Some(load_data), NavigationType::Regular, replace);
                 }
-
-                // TODO: Test javascript: urls in iframes
             }
             None => {
-                let is_javascript = load_data.url.scheme() == "javascript";
+                self.script_sender
-                if is_javascript {
+                    .send((parent_pipeline_id, ScriptMsg::LoadUrl(load_data, replace)))
-                    use url::percent_encoding::percent_decode;
+                    .unwrap();
+            }
+        }
+    }
 
+    fn eval_js_url(&self, pipeline_id: PipelineId, load_data: &mut LoadData) {
+        {
             // Turn javascript: URL into JS code to eval, according to the steps in
             // https://html.spec.whatwg.org/multipage/#javascript-protocol
 
@@ -2336,7 +2345,8 @@ impl ScriptThread {
             let script_source = percent_decode(encoded.as_bytes()).decode_utf8_lossy();
 
             // Script source is ready to be evaluated (11.)
-                    let window = self.documents.borrow().find_window(parent_pipeline_id);
+            let window = self.documents.borrow().find_window(pipeline_id);
+
             if let Some(window) = window {
                 let _ac = JSAutoCompartment::new(self.get_cx(), window.reflector().get_jsobject().get());
                 rooted!(in(self.get_cx()) let mut jsval = UndefinedValue());
@@ -2359,19 +2369,11 @@ impl ScriptThread {
                     Some(JsEvalResult::NoContent)
                 };
             }
-                }
+        };
 
-                if is_javascript {
         load_data.url = ServoUrl::parse("about:blank").unwrap();
     }
 
-                self.script_sender
-                    .send((parent_pipeline_id, ScriptMsg::LoadUrl(load_data, replace)))
-                    .unwrap();
-            }
-        }
-    }
-
     fn handle_resize_event(&self, pipeline_id: PipelineId, new_size: WindowSizeData, size_type: WindowSizeType) {
         let document = match { self.documents.borrow().find_document(pipeline_id) } {
             Some(document) => document,