Add paint metrics to Performance Timeline API

components/script/dom/performancepainttiming.rs

@@ -0,0 +1,41 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use dom::bindings::codegen::Bindings::PerformancePaintTimingBinding;
+use dom::bindings::js::Root;
+use dom::bindings::reflector::reflect_dom_object;
+use dom::bindings::str::DOMString;
+use dom::globalscope::GlobalScope;
+use dom::performanceentry::PerformanceEntry;
+use dom_struct::dom_struct;
+use script_traits::PaintMetricType;
+
+#[dom_struct]
+pub struct PerformancePaintTiming {
+    entry: PerformanceEntry,
+}
+
+impl PerformancePaintTiming {
+    fn new_inherited(metric_type: PaintMetricType, start_time: f64)
+        -> PerformancePaintTiming {
+        let name = match metric_type {
+            PaintMetricType::FirstPaint => DOMString::from("first-paint"),
+            PaintMetricType::FirstContentfulPaint => DOMString::from("first-contentful-paint"),
+        };
+        PerformancePaintTiming {
+            entry: PerformanceEntry::new_inherited(name,
+                                                   DOMString::from("paint"),
+                                                   start_time,
+                                                   0.)
+        }
+    }
+
+    #[allow(unrooted_must_root)]
+    pub fn new(global: &GlobalScope,
+               metric_type: PaintMetricType,
+               start_time: f64) -> Root<PerformancePaintTiming> {
+        let entry = PerformancePaintTiming::new_inherited(metric_type, start_time);
+        reflect_dom_object(box entry, global, PerformancePaintTimingBinding::Wrap)
+    }
+}