NQE: Use cached estimates

net/nqe/network_qualities_prefs_manager.cc

Index: net/nqe/network_qualities_prefs_manager.cc
diff --git a/net/nqe/network_qualities_prefs_manager.cc b/net/nqe/network_qualities_prefs_manager.cc
index 64c9f5c44513c87e7f019e833c406d251c5cf991..ba3036b64f401ad2571be5c0e63431381e50ffbf 100644
--- a/net/nqe/network_qualities_prefs_manager.cc
+++ b/net/nqe/network_qualities_prefs_manager.cc
@@ -56,7 +56,7 @@ NetworkQualitiesPrefsManager::NetworkQualitiesPrefsManager(
     std::unique_ptr<PrefDelegate> pref_delegate)
     : pref_delegate_(std::move(pref_delegate)),
       pref_task_runner_(base::ThreadTaskRunnerHandle::Get()),
-      prefs_(pref_delegate_->GetDictionaryValue().CreateDeepCopy()),
+      prefs_(pref_delegate_->GetDictionaryValue()),
       network_quality_estimator_(nullptr),
       read_prefs_startup_(ConvertDictionaryValueToMap(prefs_.get())),
       pref_weak_ptr_factory_(this) {
@@ -153,7 +153,7 @@ void NetworkQualitiesPrefsManager::OnChangeInCachedNetworkQualityOnPrefThread(
 ParsedPrefs NetworkQualitiesPrefsManager::ForceReadPrefsForTesting() const {
   DCHECK(pref_task_runner_->RunsTasksOnCurrentThread());
   std::unique_ptr<base::DictionaryValue> value(
-      pref_delegate_->GetDictionaryValue().CreateDeepCopy());
+      pref_delegate_->GetDictionaryValue());
   return ConvertDictionaryValueToMap(value.get());
 }