NQE: Always read prefs in cronet

components/cronet/android/cronet_url_request_context_adapter.cc

Index: components/cronet/android/cronet_url_request_context_adapter.cc
diff --git a/components/cronet/android/cronet_url_request_context_adapter.cc b/components/cronet/android/cronet_url_request_context_adapter.cc
index 24d31843dd2fa46019249d9dc0c1edf329f4e2f8..7d0bf0f5f2e7eb86a411b0f72bcf07c3f524077e 100644
--- a/components/cronet/android/cronet_url_request_context_adapter.cc
+++ b/components/cronet/android/cronet_url_request_context_adapter.cc
@@ -205,15 +205,15 @@ class NetworkQualitiesPrefDelegateImpl
   }
   std::unique_ptr<base::DictionaryValue> GetDictionaryValue() override {
     DCHECK(thread_checker_.CalledOnValidThread());
-    // TODO(tbansal): Add logic to read prefs if the embedder has enabled cached
-    // estimates.
-    return base::WrapUnique(new base::DictionaryValue());
+    UMA_HISTOGRAM_EXACT_LINEAR("NQE.Prefs.ReadCount", 1, 2);
+    return pref_service_->GetDictionary(kNetworkQualities)->CreateDeepCopy();

[xunjieli, 2017/02/07 21:05:59]

Does |pref_service_| return empty DictionaryValue if prefs are not yet loaded?

[tbansal1, 2017/02/09 17:36:26]

Yes, it will return an empty map. 
Prefs are read synchronously in Cronet and in the initial profile in Chrome, so
that should not be a problem.

   }
 
  private:
   // Schedules the writing of the lossy prefs.
   void SchedulePendingLossyWrites() {
     DCHECK(thread_checker_.CalledOnValidThread());
+    UMA_HISTOGRAM_EXACT_LINEAR("NQE.Prefs.WriteCount", 1, 2);
     pref_service_->SchedulePendingLossyWrites();
     lossy_prefs_writing_task_posted_ = false;
   }