Enable TCP preconnect and DNS preresolve on cellular.

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;
 }
@@ skipping 12 matching lines @@
 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.
+// The following two global functions determine whether prefetching
+// and prerendering are enabled, based on preferences and network type.
 
 // To be executed on the IO thread only.
 bool CanPredictNetworkActionsIO(ProfileIOData* profile_io_data);
 
 // To be executed on the UI thread only.
 bool CanPredictNetworkActionsUI(PrefService* prefs);

[mmenke, 2014/08/08 16:05:42]

I think this name is confusing, giving the preconnect is also predicting network
actions.  Suggest calling these CanPrefetch[IO/UI].

Alternatively, could be more specific with CanPrefetchAndPrerender, and rename
the other CanPreresolveAndPreconnect.  A bit wordier, but clearer.  Only
potential issue is we may use them for other decisions, too.  Anyhow, up to you.

[Bence, 2014/08/08 20:10:03]

Done.

 
+// The following two global functions determine whether TCP preconnect
+// and DNS preresolution are enabled, based on preferences.
+
+// To be executed on the IO thread only.
+bool CanPreconnectIO(ProfileIOData* profile_io_data);
+
+// To be executed on the UI thread only.
+bool CanPreconnectUI(PrefService* prefs);
+
 }  // namespace chrome_browser_net
 
 #endif  // CHROME_BROWSER_NET_PREDICTION_OPTIONS_H_