Exposing NQE on the Browser UI thread

chrome/browser/net/nqe/io_network_quality_observer.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 "chrome/browser/net/nqe/io_network_quality_observer.h"
+
+#include "base/bind.h"
+#include "base/task_runner.h"
+#include "chrome/browser/io_thread.h"
+#include "chrome/browser/net/nqe/ui_network_quality_estimator_service.h"
+
+IONetworkQualityObserver::IONetworkQualityObserver(
+    scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner,
+    base::WeakPtr<UINetworkQualityEstimatorService> service)
+    : ui_task_runner_(ui_task_runner), service_(service) {
+}
+
+IONetworkQualityObserver::~IONetworkQualityObserver() {
+  if (network_quality_estimator_)
+    network_quality_estimator_->RemoveEffectiveConnectionTypeObserver(this);
+}
+
+void IONetworkQualityObserver::InitializeOnIOThread(IOThread* io_thread) {
+  DCHECK(io_thread->globals()->network_quality_estimator);

[tbansal1, 2016/07/01 22:22:02]

Is it guaranteed that nqe will be initialized when this is called? 

[RyanSturm, 2016/07/11 22:00:19]

Acknowledged.

+  network_quality_estimator_ =
+      io_thread->globals()->network_quality_estimator->GetWeakPtr();
+  network_quality_estimator_->AddEffectiveConnectionTypeObserver(this);
+  ui_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(
+          &UINetworkQualityEstimatorService::EffectiveConnectionTypeChanged,
+          service_, network_quality_estimator_->GetEffectiveConnectionType()));
+}
+
+void IONetworkQualityObserver::OnEffectiveConnectionTypeChanged(
+    net::NetworkQualityEstimator::EffectiveConnectionType type) {
+  ui_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(
+          &UINetworkQualityEstimatorService::EffectiveConnectionTypeChanged,
+          service_, type));
+}