Make NQE a derived class of NetworkQualityProvider

components/offline_pages/core/background/network_quality_provider_stub.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/offline_pages/core/background/network_quality_provider_stub.h"
 
 namespace offline_pages {
 
 const char kOfflineNQPKey[] = "OfflineNQP";
 
@@ skipping 12 matching lines @@
 
 // static
 void NetworkQualityProviderStub::SetUserData(
     base::SupportsUserData* supports_user_data,
     std::unique_ptr<NetworkQualityProviderStub> stub) {
   DCHECK(supports_user_data);
   DCHECK(stub);
   supports_user_data->SetUserData(&kOfflineNQPKey, std::move(stub));
 }
 
-void NetworkQualityProviderStub::AddEffectiveConnectionTypeObserver(
-    net::NetworkQualityEstimator::EffectiveConnectionTypeObserver* observer) {}
-
-void NetworkQualityProviderStub::RemoveEffectiveConnectionTypeObserver(
-    net::NetworkQualityEstimator::EffectiveConnectionTypeObserver* observer) {}
-
-void NetworkQualityProviderStub::AddRTTAndThroughputEstimatesObserver(
-    net::NetworkQualityEstimator::RTTAndThroughputEstimatesObserver* observer) {
-}
-
-void NetworkQualityProviderStub::RemoveRTTAndThroughputEstimatesObserver(
-    net::NetworkQualityEstimator::RTTAndThroughputEstimatesObserver* observer) {
-}
-
 net::EffectiveConnectionType
 NetworkQualityProviderStub::GetEffectiveConnectionType() const {
   return connection_type_;
 }
 }  // namespace offline_pages