Implement support for modifying the type attribute of button elements. Fixes #9091.

components/script/dom/htmlbuttonelement.rs

@@ -27,7 +27,6 @@ use string_cache::Atom;
 use util::str::DOMString;
 
 #[derive(JSTraceable, PartialEq, Copy, Clone)]
-#[allow(dead_code)]
 #[derive(HeapSizeOf)]
 enum ButtonType {
     Submit,
@@ -50,7 +49,6 @@ impl HTMLButtonElement {
             htmlelement:
                 HTMLElement::new_inherited_with_state(IN_ENABLED_STATE,
                                                       localName, prefix, document),
-            //TODO: implement button_type in attribute_mutated
             button_type: Cell::new(ButtonType::Submit)
         }
     }
@@ -162,6 +160,22 @@ impl VirtualMethods for HTMLButtonElement {
                     }
                 }
             },
+            &atom!("type") => {
+                match mutation {
+                    AttributeMutation::Set(_) => {
+                        let value = match &**attr.value() {
+                            "reset" => ButtonType::Reset,
+                            "button" => ButtonType::Button,
+                            "menu" => ButtonType::Menu,
+                            _ => ButtonType::Submit,
+                        };
+                        self.button_type.set(value);
+                    }
+                    AttributeMutation::Removed => {
+                        self.button_type.set(ButtonType::Submit);
+                    }
+                }
+            }
             _ => {},
         }
     }

tests/wpt/metadata/html/semantics/forms/the-button-element/button-events.html.ini

@@ -1,12 +1,6 @@
 [button-events.html]
   type: testharness
-  expected: CRASH
+  expected: TIMEOUT
-  [The submit event must be fired when click a button in submit status]
-    expected: TIMEOUT
-
-  [The reset event must be fired when click a button in reset status]
-    expected: TIMEOUT
-
   [The show event must be fired when click a button in menu status]
     expected: TIMEOUT