Returning const ref instead of const value in CachedNetworkQuality::network_quality

net/base/network_quality_estimator.h

Index: net/base/network_quality_estimator.h
diff --git a/net/base/network_quality_estimator.h b/net/base/network_quality_estimator.h
index a32264f89703e90cfb600f25f82dad5ebbf8b6cc..e244eb3d3763ceb7ecd8497fa9f5b9f6d6bc6e90 100644
--- a/net/base/network_quality_estimator.h
+++ b/net/base/network_quality_estimator.h
@@ -196,7 +196,7 @@ class NET_EXPORT_PRIVATE NetworkQualityEstimator
     ~CachedNetworkQuality();
 
     // Returns the network quality associated with this cached entry.
-    const NetworkQuality network_quality() const { return network_quality_; }
+    const NetworkQuality& network_quality() const { return network_quality_; }
 
     // Returns true if this cache entry was updated before
     // |cached_network_quality|.