[Android] Simplify "network predictions" preference to a boolean value.

chrome/browser/predictors/resource_prefetch_common_unittest.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 "base/message_loop/message_loop.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/statistics_recorder.h"
 #include "chrome/browser/net/prediction_options.h"
 #include "chrome/browser/predictors/resource_prefetch_common.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor.h"
@@ skipping 287 matching lines @@
   SetPreference(NetworkPredictionOptions::NETWORK_PREDICTION_WIFI_ONLY);
   {
     scoped_ptr<NetworkChangeNotifier> mock(new MockNetworkChangeNotifierWIFI);
     TestIsPrefetchEnabled(config);
   }
   {
     scoped_ptr<NetworkChangeNotifier> mock(new MockNetworkChangeNotifier4G);
     TestIsPrefetchLearning(config);
   }
 
-  // Set preference to ALWAYS: always prefetch.
-  SetPreference(NetworkPredictionOptions::NETWORK_PREDICTION_ALWAYS);
-  {
-    scoped_ptr<NetworkChangeNotifier> mock(new MockNetworkChangeNotifierWIFI);
-    TestIsPrefetchEnabled(config);
-  }
-  {
-    scoped_ptr<NetworkChangeNotifier> mock(new MockNetworkChangeNotifier4G);
-    TestIsPrefetchEnabled(config);
-  }
-
   // Set preference to NEVER: never prefetch.
   SetPreference(NetworkPredictionOptions::NETWORK_PREDICTION_NEVER);
   {
     scoped_ptr<NetworkChangeNotifier> mock(new MockNetworkChangeNotifierWIFI);
     TestIsPrefetchLearning(config);
   }
   {
     scoped_ptr<NetworkChangeNotifier> mock(new MockNetworkChangeNotifier4G);
     TestIsPrefetchLearning(config);
   }
 }
 
 }  // namespace predictors