Switch SettingsEnforcement default back to GROUP_NO_ENFORCEMENT.

chrome/browser/prefs/chrome_pref_service_factory.cc

 // Copyright (c) 2012 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/prefs/chrome_pref_service_factory.h"
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/debug/trace_event.h"
 #include "base/file_util.h"
@@ skipping 172 matching lines @@
     SettingsEnforcementGroup group;
   } static const kEnforcementLevelMap[] = {
     { chrome_prefs::internals::kSettingsEnforcementGroupNoEnforcement,
       GROUP_NO_ENFORCEMENT },
     { chrome_prefs::internals::kSettingsEnforcementGroupEnforceOnload,
       GROUP_ENFORCE_ON_LOAD },
     { chrome_prefs::internals::kSettingsEnforcementGroupEnforceAlways,
       GROUP_ENFORCE_ALWAYS },
   };
 
+  // TODO(gab): Switch the default to GROUP_ENFORCE_ALWAYS.
+  SettingsEnforcementGroup enforcement_group = GROUP_NO_ENFORCEMENT;
+  bool group_determined_from_trial = false;
   base::FieldTrial* trial =
       base::FieldTrialList::Find(
           chrome_prefs::internals::kSettingsEnforcementTrialName);
   if (trial) {
     const std::string& group_name = trial->group_name();
     // ARRAYSIZE_UNSAFE must be used since the array is declared locally; it is
     // only unsafe because it could not trigger a compile error on some
     // non-array pointer types; this is fine since kEnforcementLevelMap is
     // clearly an array.
     for (size_t i = 0; i < ARRAYSIZE_UNSAFE(kEnforcementLevelMap); ++i) {
-      if (kEnforcementLevelMap[i].group_name == group_name)
-        return kEnforcementLevelMap[i].group;
+      if (kEnforcementLevelMap[i].group_name == group_name) {
+        enforcement_group = kEnforcementLevelMap[i].group;
+        group_determined_from_trial = true;
+        break;
+      }
     }
   }
-#if defined(OS_WIN)
-  // Default to GROUP_ENFORCE_ALWAYS in the absence of a valid value for the
-  // SettingsEnforcement field trial.
-  // TODO(gab): Switch other platforms over to this mode.
-  return GROUP_ENFORCE_ALWAYS;
-#else
-  return GROUP_NO_ENFORCEMENT;
-#endif
+  UMA_HISTOGRAM_BOOLEAN("Settings.EnforcementGroupDeterminedFromTrial",
+                        group_determined_from_trial);
+  return enforcement_group;
 }
 
 // Shows notifications which correspond to PersistentPrefStore's reading errors.
 void HandleReadError(PersistentPrefStore::PrefReadError error) {
   // Sample the histogram also for the successful case in order to get a
   // baseline on the success rate in addition to the error distribution.
   UMA_HISTOGRAM_ENUMERATION("PrefService.ReadError", error,
                             PersistentPrefStore::PREF_READ_ERROR_MAX_ENUM);
 
   if (error != PersistentPrefStore::PREF_READ_ERROR_NONE) {
@@ skipping 353 matching lines @@
   UMA_HISTOGRAM_BOOLEAN("Settings.InitializedFromMasterPrefs", success);
   return success;
 }
 
 void RegisterPrefs(PrefRegistrySimple* registry) {
   registry->RegisterInt64Pref(prefs::kProfilePreferenceResetTime, 0L);
   PrefHashStoreImpl::RegisterPrefs(registry);
 }
 
 }  // namespace chrome_prefs