Implement prediction_options.

chrome/browser/net/prediction_options.h

+// 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.
+
+#ifndef CHROME_BROWSER_NET_PREDICTION_OPTIONS_H_
+#define CHROME_BROWSER_NET_PREDICTION_OPTIONS_H_
+
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
+namespace content {
+class ResourceContext;
+}
+
+class PrefService;
+
+namespace chrome_browser_net {
+
+// Enum describing when to allow network predictions based on connection type.
+// The numerical value is stored in the prefs file, therefore the same enum
+// with the same order must be used by the platform-dependent components.
+// TODO(bnc): implement as per crbug.com/334602.
+// NETWORK_PREDICTION_UNSET means that the old preferences,
+// kNetworkPredictionEnabled and kAllowPrerender, should be observed.
+enum NetworkPredictionOptions {
+  NETWORK_PREDICTION_ALWAYS,
+  NETWORK_PREDICTION_WIFI_ONLY,
+  NETWORK_PREDICTION_NEVER,
+  NETWORK_PREDICTION_UNSET,
+};
+
+void RegisterPredictionOptionsProfilePrefs(
+    user_prefs::PrefRegistrySyncable* registry);
+
+// The following two global functions determine whether predictive network
+// actions are enabled, based on preferences and network type.
+
+// To be executed on the IO thread only.
+bool CanPredictNetworkActionsIO(content::ResourceContext* resource_context);
+
+// To be executed on the UI thread only.
+bool CanPredictNetworkActionsUI(PrefService* prefs);
+
+}  // namespace chrome_browser_net
+
+#endif  // CHROME_BROWSER_NET_PREDICTION_OPTIONS_H_