Implement prediction_options.

chrome/browser/net/prediction_helper.cc

+// Copyright (c) 2014 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/prediction_helper.h"
+
+#include "base/prefs/pref_service.h"
+#include "chrome/browser/net/predictor.h"
+#include "chrome/browser/profiles/profile_io_data.h"
+#include "chrome/common/pref_names.h"
+#include "components/pref_registry/pref_registry_syncable.h"
+#include "net/base/network_change_notifier.h"
+
+namespace {
+
+bool CanPredictNetworkActions(int AllowNetworkPrediction,
+    bool NetworkPredictionEnabled) {
+  switch (AllowNetworkPrediction) {
+    case chrome_browser_net::Predictor::NETWORK_PREDICTION_ALWAYS:
+      return true;
+    case chrome_browser_net::Predictor::NETWORK_PREDICTION_WIFI_ONLY:
+      return !net::NetworkChangeNotifier::IsConnectionCellular(
+          net::NetworkChangeNotifier::GetConnectionType());
+    case chrome_browser_net::Predictor::NETWORK_PREDICTION_NEVER:
+      return false;
+    case chrome_browser_net::Predictor::NETWORK_PREDICTION_UNSET:
+      return NetworkPredictionEnabled;
+    default:
+      // Unknown kAllowNetworkPrediction value, this should not happen.
+      DCHECK(false);
+      return false;

[jkarlin, 2014/06/26 16:28:52]

DCHECK(false) with:
NOTREACHED() << "Unknown kAllowNetworkPrediction value.";

[Bence, 2014/06/26 20:02:06]

Done.

+  }
+}
+
+}  // anonymous namespace
+
+namespace chrome_browser_net {
+
+void RegisterPredictionHelperProfilePrefs(
+    user_prefs::PrefRegistrySyncable* registry) {
+  registry->RegisterIntegerPref(
+      prefs::kAllowNetworkPrediction,
+      chrome_browser_net::Predictor::NETWORK_PREDICTION_UNSET,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+}
+
+// To be executed on the IO thread only.
+bool CanPredictNetworkActionsIO(content::ResourceContext* resource_context) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
+  ProfileIOData* io_data = ProfileIOData::FromResourceContext(resource_context);
+  if (io_data == NULL)
+    return false;
+  return CanPredictNetworkActions(
+      io_data->allow_network_prediction()->GetValue(),
+      io_data->network_prediction_enabled()->GetValue());
+}
+
+// To be executed on the UI thread only.
+bool CanPredictNetworkActionsUI(PrefService* prefs) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  return CanPredictNetworkActions(
+      prefs->GetInteger(prefs::kAllowNetworkPrediction),
+      prefs->GetBoolean(prefs::kNetworkPredictionEnabled));
+}
+
+}  // namespace chrome_browser_net