NQE: Notify observer as soon as it is added

chrome/browser/net/nqe/ui_network_quality_estimator_service.h

Index: chrome/browser/net/nqe/ui_network_quality_estimator_service.h
diff --git a/chrome/browser/net/nqe/ui_network_quality_estimator_service.h b/chrome/browser/net/nqe/ui_network_quality_estimator_service.h
index bae6866aa0b3b896224818e4a436548c4c1b3dd8..086ba17dc1620eff498f18004d284c0c06900eda 100644
--- a/chrome/browser/net/nqe/ui_network_quality_estimator_service.h
+++ b/chrome/browser/net/nqe/ui_network_quality_estimator_service.h
@@ -37,7 +37,8 @@ class UINetworkQualityEstimatorService
   // Must be called on the UI thread.
   net::EffectiveConnectionType GetEffectiveConnectionType() const override;
   // Must be called on the UI thread. |observer| will be notified on the UI
-  // thread.
+  // thread.  |observer| would be notified of the current effective connection
+  // type in the next message pump, if it is still registered as an observer.
   void AddEffectiveConnectionTypeObserver(
       net::NetworkQualityEstimator::EffectiveConnectionTypeObserver* observer)
       override;
@@ -65,6 +66,12 @@ class UINetworkQualityEstimatorService
  private:
   class IONetworkQualityObserver;
 
+  // Notifies |observer| of the current effective connection type if |observer|
+  // is still registered as an observer.
+  void NotifyEffectiveConnectionTypeObserverIfPresent(
+      net::NetworkQualityEstimator::EffectiveConnectionTypeObserver* observer)
+      const;
+
   // KeyedService implementation:
   void Shutdown() override;