Implement prediction_options.

chrome/browser/net/prediction_options.cc

Index: chrome/browser/net/prediction_options.cc
diff --git a/chrome/browser/net/prediction_options.cc b/chrome/browser/net/prediction_options.cc
new file mode 100644
index 0000000000000000000000000000000000000000..53769cf3c7eab65f9ffe60e18733a1298112e8a1
--- /dev/null
+++ b/chrome/browser/net/prediction_options.cc
@@ -0,0 +1,68 @@
+// Copyright 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_options.h"
+
+#include "base/logging.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 "content/public/browser/browser_thread.h"
+#include "net/base/network_change_notifier.h"
+
+namespace {
+
+// Since looking up preferences and current network connection are presumably
+// both cheap, we do not cache them here.
+bool CanPredictNetworkActions(int NetworkPredictionOptions,
+                              bool NetworkPredictionEnabled) {
+  switch (NetworkPredictionOptions) {
+    case chrome_browser_net::NETWORK_PREDICTION_ALWAYS:
+      return true;
+    case chrome_browser_net::NETWORK_PREDICTION_WIFI_ONLY:
+      return !net::NetworkChangeNotifier::IsConnectionCellular(
+          net::NetworkChangeNotifier::GetConnectionType());
+    case chrome_browser_net::NETWORK_PREDICTION_NEVER:
+      return false;
+    case chrome_browser_net::NETWORK_PREDICTION_UNSET:
+      return NetworkPredictionEnabled;
+    default:
+      NOTREACHED() << "Unknown kNetworkPredictionOptions value.";
+      return false;
+  }
+}
+
+}  // namespace
+
+namespace chrome_browser_net {
+
+void RegisterPredictionOptionsProfilePrefs(
+    user_prefs::PrefRegistrySyncable* registry) {
+  registry->RegisterIntegerPref(
+      prefs::kNetworkPredictionOptions,
+      chrome_browser_net::NETWORK_PREDICTION_UNSET,
+      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+}
+
+bool CanPredictNetworkActionsIO(content::ResourceContext* resource_context) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
+  DCHECK(resource_context);
+
+  ProfileIOData* io_data = ProfileIOData::FromResourceContext(resource_context);
+  return CanPredictNetworkActions(
+      io_data->network_prediction_options()->GetValue(),
+      io_data->network_prediction_enabled()->GetValue());
+}
+
+bool CanPredictNetworkActionsUI(PrefService* prefs) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  DCHECK(prefs);
+  return CanPredictNetworkActions(
+      prefs->GetInteger(prefs::kNetworkPredictionOptions),
+      prefs->GetBoolean(prefs::kNetworkPredictionEnabled));
+}
+
+}  // namespace chrome_browser_net