Enable ServerTiming support

third_party/WebKit/Source/core/frame/LocalDOMWindow.h

Index: third_party/WebKit/Source/core/frame/LocalDOMWindow.h
diff --git a/third_party/WebKit/Source/core/frame/LocalDOMWindow.h b/third_party/WebKit/Source/core/frame/LocalDOMWindow.h
index 90d1ab9378c0da8b31f197d4c31767d818a3a617..85dc0e9f5d6c8d0178ce1c0984dffb44f4a5f638 100644
--- a/third_party/WebKit/Source/core/frame/LocalDOMWindow.h
+++ b/third_party/WebKit/Source/core/frame/LocalDOMWindow.h
@@ -316,6 +316,9 @@ class CORE_EXPORT LocalDOMWindow final : public DOMWindow,
 
   FloatSize GetViewportSize(IncludeScrollbarsInRect) const;
 
+  void SetHasLoadEventFired() { has_load_event_fired_ = true; }
+  bool HasLoadEventFired() { return has_load_event_fired_; }
+
  protected:
   // EventTarget overrides.
   void AddedEventListener(const AtomicString& event_type,
@@ -346,6 +349,7 @@ class CORE_EXPORT LocalDOMWindow final : public DOMWindow,
   TaskRunnerTimer<LocalDOMWindow> unused_preloads_timer_;
 
   bool should_print_when_finished_loading_;
+  bool has_load_event_fired_ = false;
 
   mutable Member<Screen> screen_;
   mutable Member<History> history_;