Update "Predict network actions" UI setting.

chrome/browser/policy/policy_prefs_browsertest.cc

Index: chrome/browser/policy/policy_prefs_browsertest.cc
diff --git a/chrome/browser/policy/policy_prefs_browsertest.cc b/chrome/browser/policy/policy_prefs_browsertest.cc
index 4becba9e1c473d0fcc1e56f6962a403e9a501f95..a260914c04b619b7cc03885d2013e5873f2deae5 100644
--- a/chrome/browser/policy/policy_prefs_browsertest.cc
+++ b/chrome/browser/policy/policy_prefs_browsertest.cc
@@ -28,6 +28,7 @@
 #include "chrome/browser/search_engines/template_url_service_factory.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/common/pref_names.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "components/policy/core/browser/browser_policy_connector.h"
@@ -720,6 +721,17 @@ IN_PROC_BROWSER_TEST_P(PolicyPrefIndicatorTest, CheckPolicyIndicators) {
               prefs->FindPreference((*pref_mapping)->pref().c_str());
           ASSERT_TRUE(pref);
 
+          // This hack is necessary because
+          // BrowserOptionsHandler::MigrateNetworkPredictionOptions migrates the
+          // deprecated kNetworkPredicitonEnabled preference into
+          // kNetworkPredictionOptions, setting a user value.

[bartfab (slow), 2014/08/04 16:44:13]

User values should be set by the user. The migration you described sounds
dangerous. It means that policy-supplied values end up getting stored as if they
had been set by the user. Here are some of the problems that can lead to:

* Any controlled setting indicator keyed by the pref will not show up the
enterprise icon, because the value will look like it was set by the user, not by
policy.
* The user will be able to change the policy-supplied value.
* How about the following scenario: The admin sets the policy to a value now,
the migration code copies this to a user value. Later, after the migration code
has been removed, the admin unsets the policy value. Since there is no migration
code anymore, the value that had been copied stays.

[Bence, 2014/08/04 20:35:32]

Done.

+          // TODO(bnc): https://crbug.com/334602  Remove this hack once
+          // migration code is removed.
+          if ((*pref_mapping)->pref().compare(
+                  prefs::kNetworkPredictionOptions) == 0) {
+            prefs->ClearPref((*pref_mapping)->pref().c_str());
+          }
+
           // Check that the appropriate controlled setting indicator is shown
           // when a value is recommended by policy and the user has not
           // overridden the recommendation.