Coarser levels for the SettingsEnforcement field trial.

chrome/browser/prefs/chrome_pref_service_factory.cc

Index: chrome/browser/prefs/chrome_pref_service_factory.cc
diff --git a/chrome/browser/prefs/chrome_pref_service_factory.cc b/chrome/browser/prefs/chrome_pref_service_factory.cc
index dd4124cee7196218a389e872df5965cdbe5599a4..644381278f96ed317d254b671030af9934e82e09 100644
--- a/chrome/browser/prefs/chrome_pref_service_factory.cc
+++ b/chrome/browser/prefs/chrome_pref_service_factory.cc
@@ -69,27 +69,27 @@ namespace {
 const PrefHashFilter::TrackedPreferenceMetadata kTrackedPrefs[] = {
   {
     0, prefs::kShowHomeButton,
-    PrefHashFilter::ENFORCE_ALL,
+    PrefHashFilter::ENFORCE_ON_LOAD,
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
   {
     1, prefs::kHomePageIsNewTabPage,
-    PrefHashFilter::ENFORCE_ALL,
+    PrefHashFilter::ENFORCE_ON_LOAD,
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
   {
     2, prefs::kHomePage,
-    PrefHashFilter::ENFORCE_ALL,
+    PrefHashFilter::ENFORCE_ON_LOAD,
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
   {
     3, prefs::kRestoreOnStartup,
-    PrefHashFilter::ENFORCE_ALL,
+    PrefHashFilter::ENFORCE_ON_LOAD,
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
   {
     4, prefs::kURLsToRestoreOnStartup,
-    PrefHashFilter::ENFORCE_ALL,
+    PrefHashFilter::ENFORCE_ON_LOAD,
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
   {
@@ -99,33 +99,33 @@ const PrefHashFilter::TrackedPreferenceMetadata kTrackedPrefs[] = {
   },
   {
     6, prefs::kGoogleServicesLastUsername,
-    PrefHashFilter::ENFORCE_ALL,
+    PrefHashFilter::ENFORCE_ON_LOAD,
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
   {
     7, prefs::kSearchProviderOverrides,
-    PrefHashFilter::ENFORCE_ALL,
+    PrefHashFilter::ENFORCE_ON_LOAD,
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
   {
     8, prefs::kDefaultSearchProviderSearchURL,
-    PrefHashFilter::ENFORCE_ALL,
+    PrefHashFilter::ENFORCE_ON_LOAD,
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
   {
     9, prefs::kDefaultSearchProviderKeyword,
-    PrefHashFilter::ENFORCE_ALL,
+    PrefHashFilter::ENFORCE_ON_LOAD,
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
   {
     10, prefs::kDefaultSearchProviderName,
-    PrefHashFilter::ENFORCE_ALL,
+    PrefHashFilter::ENFORCE_ON_LOAD,
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
 #if !defined(OS_ANDROID)
   {
     11, prefs::kPinnedTabs,
-    PrefHashFilter::ENFORCE_ALL,
+    PrefHashFilter::ENFORCE_ON_LOAD,
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
 #endif
@@ -136,7 +136,7 @@ const PrefHashFilter::TrackedPreferenceMetadata kTrackedPrefs[] = {
   },
   {
     13, prefs::kProfileResetPromptMemento,
-    PrefHashFilter::ENFORCE_ALL,
+    PrefHashFilter::ENFORCE_ON_LOAD,
     PrefHashFilter::TRACKING_STRATEGY_ATOMIC
   },
 };
@@ -146,33 +146,22 @@ const size_t kTrackedPrefsReportingIDsCount = 14;
 COMPILE_ASSERT(kTrackedPrefsReportingIDsCount >= arraysize(kTrackedPrefs),
                need_to_increment_ids_count);
 
-PrefHashFilter::EnforcementLevel GetSettingsEnforcementLevel() {
+enum SettingsEnforcementGroup {
+  GROUP_NO_ENFORCEMENT,
+  GROUP_ENFORCE_ON_LOAD,
+  GROUP_ENFORCE_ALWAYS

[robertshield, 2014/02/11 21:16:40]

Comments re. what these mean plz.

[gab, 2014/02/11 21:25:58]

Done.

+};
+
+SettingsEnforcementGroup GetSettingsEnforcementGroup() {
   static const char kSettingsEnforcementExperiment[] = "SettingsEnforcement";
   struct {
-    const char* level_name;
-    PrefHashFilter::EnforcementLevel level;
+    const char* group_name;
+    SettingsEnforcementGroup group;
   } static const kEnforcementLevelMap[] = {
-    {
-      "no_enforcement",
-      PrefHashFilter::NO_ENFORCEMENT
-    },
-    {
-      "enforce",
-      PrefHashFilter::ENFORCE
-    },
-    {
-      "enforce_no_seeding",
-      PrefHashFilter::ENFORCE_NO_SEEDING
-    },
-    {
-      "enforce_no_seeding_no_migration",
-      PrefHashFilter::ENFORCE_NO_SEEDING_NO_MIGRATION
-    },
+    { "no_enforcement", GROUP_NO_ENFORCEMENT },
+    { "enforce_on_load", GROUP_ENFORCE_ON_LOAD },
+    { "enforce_always", GROUP_ENFORCE_ALWAYS },

[robertshield, 2014/02/11 21:16:40]

GROUP_ENFORCE_ALWAYS isn't currently used, tell me again why we need it in this
CL?

[gab, 2014/02/11 21:25:58]

Added TODO above.

   };
-  COMPILE_ASSERT(ARRAYSIZE_UNSAFE(kEnforcementLevelMap) ==
-                     (PrefHashFilter::ENFORCE_ALL -
-                      PrefHashFilter::NO_ENFORCEMENT),
-                 missing_enforcement_level);
 
   base::FieldTrial* trial =
       base::FieldTrialList::Find(kSettingsEnforcementExperiment);
@@ -183,17 +172,17 @@ PrefHashFilter::EnforcementLevel GetSettingsEnforcementLevel() {
     // 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].level_name == group_name)
-        return kEnforcementLevelMap[i].level;
+      if (kEnforcementLevelMap[i].group_name == group_name)
+        return kEnforcementLevelMap[i].group;
     }
   }
 #if defined(OS_WIN)
-  // Default to ENFORCE_ALL in the absence of a valid value for the
+  // 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 PrefHashFilter::ENFORCE_ALL;
+  return GROUP_ENFORCE_ALWAYS;
 #else
-  return PrefHashFilter::NO_ENFORCEMENT;
+  return GROUP_NO_ENFORCEMENT;
 #endif
 }
 
@@ -266,11 +255,14 @@ scoped_ptr<PrefHashStoreImpl> GetPrefHashStoreImpl(
 
 scoped_ptr<PrefHashFilter> CreatePrefHashFilter(
     scoped_ptr<PrefHashStore> pref_hash_store) {
+  const PrefHashFilter::EnforcementLevel enforcement_level =
+      GetSettingsEnforcementGroup() == GROUP_NO_ENFORCEMENT ?
+          PrefHashFilter::NO_ENFORCEMENT : PrefHashFilter::ENFORCE_ON_LOAD;

[robertshield, 2014/02/11 21:16:40]

Can this still live in a GetSettingsEnforcementLevel function? I kind of liked
having all the logic for the enforcement level computation in one place.

[gab, 2014/02/11 21:25:58]

No; GROUP_ENFORCE_ALWAYS means to not do unloaded profile initialization (which
is not a concept PrefHashFilter knows about); that group will be handled in this
file only.

   return make_scoped_ptr(new PrefHashFilter(pref_hash_store.Pass(),
                                             kTrackedPrefs,
                                             arraysize(kTrackedPrefs),
                                             kTrackedPrefsReportingIDsCount,
-                                            GetSettingsEnforcementLevel()));
+                                            enforcement_level));
 }
 
 void PrepareBuilder(