Blink changes to record interest rects for http://w3c.github.io/frame-timing/

public/web/WebWidget.h

Index: public/web/WebWidget.h
diff --git a/public/web/WebWidget.h b/public/web/WebWidget.h
index 691715e22835e4cf949acccb790e251aa9a58433..356dc37e840c30f8c351ea048a4eb4c49a5311c9 100644
--- a/public/web/WebWidget.h
+++ b/public/web/WebWidget.h
@@ -160,6 +160,14 @@ public:
         float scaleFactor,
         float topControlsShownRatioDelta) { }
 
+    // Records composite or render events for the Performance Timeline.
+    // See http://w3c.github.io/frame-timing/ for definition of terms.
+    enum FrameTimingEventType {
+        CompositeEvent,
+        RenderEvent,
+    };
+    virtual void recordFrameTimingEvent(FrameTimingEventType eventType, int64_t RectId, const WebVector<std::pair<int, double>>& events) { }
+
     // Called to inform the WebWidget that mouse capture was lost.
     virtual void mouseCaptureLost() { }