Store parser's current line when script elements are created.

Use the newly stored line as the starting line number when
evaluating JS. This ensures that inline scripts will report
errors with meaningful line numbers.

components/script/dom/servoparser/html.rs

@@ -52,6 +52,7 @@ impl Tokenizer {
         let sink = Sink {
             base_url: url,
             document: JS::from_ref(document),
+            current_line: 1,
         };
 
         let options = TreeBuilderOpts {
@@ -122,6 +123,7 @@ unsafe impl JSTraceable for HtmlTokenizer<TreeBuilder<JS<Node>, Sink>> {
 struct Sink {
     base_url: ServoUrl,
     document: JS<Document>,
+    current_line: u64,
 }
 
 impl TreeSink for Sink {
@@ -156,7 +158,7 @@ impl TreeSink for Sink {
     fn create_element(&mut self, name: QualName, attrs: Vec<Attribute>)
             -> JS<Node> {
         let elem = Element::create(name, None, &*self.document,
-                                   ElementCreator::ParserCreated);
+                                   ElementCreator::ParserCreated(self.current_line));
 
         for attr in attrs {
             elem.set_attribute_from_parser(attr.name, DOMString::from(String::from(attr.value)), None);
@@ -234,6 +236,10 @@ impl TreeSink for Sink {
         }
     }
 
+    fn set_current_line(&mut self, line_number: u64) {
+        self.current_line = line_number;
+    }
+
     fn pop(&mut self, node: JS<Node>) {
         let node = Root::from_ref(&*node);
         vtable_for(&node).pop();