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

chrome/browser/prefetch/prefetch_browsertest.cc

 // Copyright 2013 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/base_switches.h"
 #include "base/command_line.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/net/prediction_options.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
@@ skipping 74 matching lines @@
 
 class PrefetchBrowserTestPredictionDisabled : public PrefetchBrowserTestBase {
  public:
   PrefetchBrowserTestPredictionDisabled() : PrefetchBrowserTestBase(true) {}
 };
 
 // Prefetch is disabled via field experiment.  Prefetch should be dropped.
 IN_PROC_BROWSER_TEST_F(PrefetchBrowserTestPredictionDisabled,
                        ExperimentDisabled) {
   EXPECT_TRUE(RunPrefetchExperiment(false, browser()));
-  // Should not prefetch even if preference is ALWAYS.
-  SetPreference(NetworkPredictionOptions::NETWORK_PREDICTION_ALWAYS);
+  // Should not prefetch even if preference is WIFI_ONLY.
+  SetPreference(NetworkPredictionOptions::NETWORK_PREDICTION_WIFI_ONLY);
   EXPECT_TRUE(RunPrefetchExperiment(false, browser()));
 }
 
 // Prefetch should be allowed depending on preference and network type.
 IN_PROC_BROWSER_TEST_F(PrefetchBrowserTestPrediction, PreferenceWorks) {
   // Set real NetworkChangeNotifier singleton aside.
   scoped_ptr<NetworkChangeNotifier::DisableForTest> disable_for_test(
       new NetworkChangeNotifier::DisableForTest);
 
   // Preference defaults to WIFI_ONLY: prefetch when not on cellular.
   {
     scoped_ptr<NetworkChangeNotifier> mock(new MockNetworkChangeNotifierWIFI);
     EXPECT_TRUE(RunPrefetchExperiment(true, browser()));
   }
   {
     scoped_ptr<NetworkChangeNotifier> mock(new MockNetworkChangeNotifier4G);
     EXPECT_TRUE(RunPrefetchExperiment(false, browser()));
   }
 
-  // Set preference to ALWAYS: always prefetch.

[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.

-  SetPreference(NetworkPredictionOptions::NETWORK_PREDICTION_ALWAYS);
-  {
-    scoped_ptr<NetworkChangeNotifier> mock(new MockNetworkChangeNotifierWIFI);
-    EXPECT_TRUE(RunPrefetchExperiment(true, browser()));
-  }
-  {
-    scoped_ptr<NetworkChangeNotifier> mock(new MockNetworkChangeNotifier4G);
-    EXPECT_TRUE(RunPrefetchExperiment(true, browser()));
-  }
-
   // Set preference to NEVER: never prefetch.
   SetPreference(NetworkPredictionOptions::NETWORK_PREDICTION_NEVER);
   {
     scoped_ptr<NetworkChangeNotifier> mock(new MockNetworkChangeNotifierWIFI);
     EXPECT_TRUE(RunPrefetchExperiment(false, browser()));
   }
   {
     scoped_ptr<NetworkChangeNotifier> mock(new MockNetworkChangeNotifier4G);
     EXPECT_TRUE(RunPrefetchExperiment(false, browser()));
   }
 }
 
 // Bug 339909: When in incognito mode the browser crashed due to an
 // uninitialized preference member. Verify that it no longer does.
 IN_PROC_BROWSER_TEST_F(PrefetchBrowserTestPrediction, IncognitoTest) {
   Profile* incognito_profile = browser()->profile()->GetOffTheRecordProfile();
   Browser* incognito_browser =
       new Browser(Browser::CreateParams(incognito_profile));
 
   // Navigate just to have a tab in this window, otherwise there is no
   // WebContents for the incognito browser.
   OpenURLOffTheRecord(browser()->profile(), GURL("about:blank"));
 
   EXPECT_TRUE(RunPrefetchExperiment(true, incognito_browser));
 }
 
 }  // namespace