Enable TCP preconnect and DNS preresolve on cellular.

chrome/browser/net/prediction_options.cc

 // 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/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) {
+bool CanPrefetchAndPrerender(int network_prediction_options,
+                             bool network_prediction_enabled) {
+  switch (network_prediction_options) {
     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;
+      return network_prediction_enabled;
     default:
       NOTREACHED() << "Unknown kNetworkPredictionOptions value.";
       return false;
+  }
+}
+
+bool CanPreresolveAndPreconnect(int network_prediction_options,
+                                bool network_prediction_enabled) {
+  switch (network_prediction_options) {
+    case chrome_browser_net::NETWORK_PREDICTION_ALWAYS:
+      return true;
+    // DNS preresolution and TCP preconnect are performed even on cellular
+    // networks if the user setting is WIFI_ONLY.
+    case chrome_browser_net::NETWORK_PREDICTION_WIFI_ONLY:
+      return true;
+    case chrome_browser_net::NETWORK_PREDICTION_NEVER:
+      return false;
+    case chrome_browser_net::NETWORK_PREDICTION_UNSET:
+      return network_prediction_enabled;
+    default:
+      NOTREACHED() << "Unknown kNetworkPredictionOptions value.";
+      return false;
   }
 }
 
 }  // namespace
 
 namespace chrome_browser_net {
 
 void RegisterPredictionOptionsProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterIntegerPref(
@@ skipping 16 matching lines @@
 
   bool value = false;
   if (network_prediction_enabled->GetAsBoolean(&value)) {
     pref_service->SetInteger(
         prefs::kNetworkPredictionOptions,
         value ? chrome_browser_net::NETWORK_PREDICTION_WIFI_ONLY
               : chrome_browser_net::NETWORK_PREDICTION_NEVER);
   }
 }
 
-bool CanPredictNetworkActionsIO(ProfileIOData* profile_io_data) {
+bool CanPrefetchAndPrerenderIO(ProfileIOData* profile_io_data) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
   DCHECK(profile_io_data);
-
-  return CanPredictNetworkActions(
+  return CanPrefetchAndPrerender(
       profile_io_data->network_prediction_options()->GetValue(),
       profile_io_data->network_prediction_enabled()->GetValue());
 }
 
-bool CanPredictNetworkActionsUI(PrefService* prefs) {
+bool CanPrefetchAndPrerenderUI(PrefService* prefs) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   DCHECK(prefs);
-  return CanPredictNetworkActions(
+  return CanPrefetchAndPrerender(
       prefs->GetInteger(prefs::kNetworkPredictionOptions),
       prefs->GetBoolean(prefs::kNetworkPredictionEnabled));
 }
+
+bool CanPredictNetworkActionsUI(PrefService* prefs) {
+  return CanPrefetchAndPrerenderUI(prefs);
+}
+
+bool CanPreresolveAndPreconnectIO(ProfileIOData* profile_io_data) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
+  DCHECK(profile_io_data);
+  return CanPreresolveAndPreconnect(
+      profile_io_data->network_prediction_options()->GetValue(),
+      profile_io_data->network_prediction_enabled()->GetValue());
+}
+
+bool CanPreresolveAndPreconnectUI(PrefService* prefs) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  DCHECK(prefs);
+  return CanPreresolveAndPreconnect(
+      prefs->GetInteger(prefs::kNetworkPredictionOptions),
+      prefs->GetBoolean(prefs::kNetworkPredictionEnabled));
+}
 
 }  // namespace chrome_browser_net