Make NQE a derived class of NetworkQualityProvider

chrome/browser/io_thread.h

Index: chrome/browser/io_thread.h
diff --git a/chrome/browser/io_thread.h b/chrome/browser/io_thread.h
index 4f2db705cfc8920c71c358b0c96eff7e1c4bc07a..0797746a7d7576b950a7ce88c73d8658081960aa 100644
--- a/chrome/browser/io_thread.h
+++ b/chrome/browser/io_thread.h
@@ -83,6 +83,7 @@ class HttpAuthPreferences;
 class LoggingNetworkChangeObserver;
 class NetworkQualityEstimator;
 class ProxyConfigService;
+class RTTAndThroughputEstimatesObserver;
 class SSLConfigService;
 class URLRequestContext;
 class URLRequestContextGetter;
@@ -154,8 +155,7 @@ class IOThread : public content::BrowserThreadDelegate {
 #endif
     std::unique_ptr<net::HostMappingRules> host_mapping_rules;
     std::unique_ptr<net::NetworkQualityEstimator> network_quality_estimator;
-    std::unique_ptr<
-        net::NetworkQualityEstimator::RTTAndThroughputEstimatesObserver>
+    std::unique_ptr<net::RTTAndThroughputEstimatesObserver>
         network_quality_observer;
 
     // NetErrorTabHelper uses |dns_probe_service| to send DNS probes when a