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

chrome/browser/predictors/resource_prefetch_common_unittest.cc

Index: chrome/browser/predictors/resource_prefetch_common_unittest.cc
diff --git a/chrome/browser/predictors/resource_prefetch_common_unittest.cc b/chrome/browser/predictors/resource_prefetch_common_unittest.cc
index e6d6e333b6789805effcd766126990048c5d1099..92a5dbf80d085d2cf83618c41859267a72e00d87 100644
--- a/chrome/browser/predictors/resource_prefetch_common_unittest.cc
+++ b/chrome/browser/predictors/resource_prefetch_common_unittest.cc
@@ -305,17 +305,6 @@ TEST_F(ResourcePrefetchCommonTest, FieldTrialPrefetchingDisabledByNetwork) {
     TestIsPrefetchLearning(config);
   }
 
-  // Set preference to ALWAYS: always prefetch.
-  SetPreference(NetworkPredictionOptions::NETWORK_PREDICTION_ALWAYS);

[newt (away), 2016/02/22 19:45:38]

The "ALWAYS" state is being merged into the WIFI_ONLY state. Right now, their
behavior is identical. In a future CL, the states will actually be merged.

-  {
-    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);
   {