Multi-strategy based tracking.

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/debug/trace_event.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/default_pref_store.h"
 #include "base/prefs/json_pref_store.h"
 #include "base/prefs/pref_notifier_impl.h"
 #include "base/prefs/pref_registry.h"
 #include "base/prefs/pref_service.h"
 #include "base/prefs/pref_value_store.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/prefs/command_line_pref_store.h"
 #include "chrome/browser/prefs/pref_hash_filter.h"
 #include "chrome/browser/prefs/pref_hash_store.h"
 #include "chrome/browser/prefs/pref_model_associator.h"
 #include "chrome/browser/prefs/pref_service_syncable.h"
 #include "chrome/browser/prefs/pref_service_syncable_factory.h"
+#include "chrome/browser/prefs/tracked_preference_helper.h"
 #include "chrome/browser/ui/profile_error_dialog.h"
 #include "chrome/common/pref_names.h"
 #include "components/user_prefs/pref_registry_syncable.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 
 #if defined(ENABLE_CONFIGURATION_POLICY)
 #include "chrome/browser/policy/browser_policy_connector.h"
 #include "components/policy/core/browser/configuration_policy_pref_store.h"
 #include "components/policy/core/common/policy_types.h"
 #endif
 
 #if defined(ENABLE_MANAGED_USERS)
 #include "chrome/browser/managed_mode/supervised_user_pref_store.h"
 #endif
 
 using content::BrowserContext;
 using content::BrowserThread;
 
 namespace {
 
 // These preferences must be kept in sync with the TrackedPreference enum in
 // tools/metrics/histograms/histograms.xml. To add a new preference, append it
 // to the array and add a corresponding value to the histogram enum. Each
 // tracked preference must be given a unique reporting ID.
-const PrefHashFilter::TrackedPreference kTrackedPrefs[] = {
-  { 0, prefs::kShowHomeButton, true },
-  { 1, prefs::kHomePageIsNewTabPage, true },
-  { 2, prefs::kHomePage, true },
-  { 3, prefs::kRestoreOnStartup, true },
-  { 4, prefs::kURLsToRestoreOnStartup, true },
-  { 5, prefs::kExtensionsPref, false },
-  { 6, prefs::kGoogleServicesLastUsername, true },
-  { 7, prefs::kSearchProviderOverrides, true },
-  { 8, prefs::kDefaultSearchProviderSearchURL, true },
-  { 9, prefs::kDefaultSearchProviderKeyword, true },
-  { 10, prefs::kDefaultSearchProviderName, true },
+const PrefHashFilter::TrackedPreferenceMetadata kTrackedPrefs[] = {
+  {
+    0, prefs::kShowHomeButton, true,
+    PrefHashFilter::TRACKING_STRATEGY_ATOMIC
+  },
+  {
+    1, prefs::kHomePageIsNewTabPage, true,
+    PrefHashFilter::TRACKING_STRATEGY_ATOMIC
+  },
+  {
+    2, prefs::kHomePage, true,
+    PrefHashFilter::TRACKING_STRATEGY_ATOMIC
+  },
+  {
+    3, prefs::kRestoreOnStartup, true,
+    PrefHashFilter::TRACKING_STRATEGY_ATOMIC
+  },
+  {
+    4, prefs::kURLsToRestoreOnStartup, true,
+    PrefHashFilter::TRACKING_STRATEGY_ATOMIC
+  },
+  {
+    5, prefs::kExtensionsPref, false,
+    PrefHashFilter::TRACKING_STRATEGY_SPLIT
+  },
+  {
+    6, prefs::kGoogleServicesLastUsername, true,
+    PrefHashFilter::TRACKING_STRATEGY_ATOMIC
+  },
+  {
+    7, prefs::kSearchProviderOverrides, true,
+    PrefHashFilter::TRACKING_STRATEGY_ATOMIC
+  },
+  {
+    8, prefs::kDefaultSearchProviderSearchURL, true,
+    PrefHashFilter::TRACKING_STRATEGY_ATOMIC
+  },
+  {
+    9, prefs::kDefaultSearchProviderKeyword, true,
+    PrefHashFilter::TRACKING_STRATEGY_ATOMIC
+  },
+  {
+    10, prefs::kDefaultSearchProviderName, true,
+    PrefHashFilter::TRACKING_STRATEGY_ATOMIC
+  },
 #if !defined(OS_ANDROID)
-  { 11, prefs::kPinnedTabs, true },
+  {
+    11, prefs::kPinnedTabs, true,
+    PrefHashFilter::TRACKING_STRATEGY_ATOMIC
+  },
 #endif
-  { 12, prefs::kExtensionKnownDisabled, true },
-  { 13, prefs::kProfileResetPromptMemento, true },
+  {
+    12, prefs::kExtensionKnownDisabled, true,
+    PrefHashFilter::TRACKING_STRATEGY_ATOMIC
+  },
+  {
+    13, prefs::kProfileResetPromptMemento, true,
+    PrefHashFilter::TRACKING_STRATEGY_ATOMIC
+  },
 };
 
 // The count of tracked preferences IDs across all platforms.
 const size_t kTrackedPrefsReportingIDsCount = 14;
 COMPILE_ASSERT(kTrackedPrefsReportingIDsCount >= arraysize(kTrackedPrefs),
                need_to_increment_ids_count);
 
-PrefHashFilter::EnforcementLevel GetSettingsEnforcementLevel() {
+TrackedPreferenceHelper::EnforcementLevel GetSettingsEnforcementLevel() {
   static const char kSettingsEnforcementExperiment[] = "SettingsEnforcement";
   struct {
     const char* level_name;
-    PrefHashFilter::EnforcementLevel level;
+    TrackedPreferenceHelper::EnforcementLevel level;
   } static const kEnforcementLevelMap[] = {
     {
       "no_enforcement",
-      PrefHashFilter::NO_ENFORCEMENT
+      TrackedPreferenceHelper::NO_ENFORCEMENT
     },
     {
       "enforce",
-      PrefHashFilter::ENFORCE
+      TrackedPreferenceHelper::ENFORCE
     },
     {
       "enforce_no_seeding",
-      PrefHashFilter::ENFORCE_NO_SEEDING
+      TrackedPreferenceHelper::ENFORCE_NO_SEEDING
     },
     {
       "enforce_no_seeding_no_migration",
-      PrefHashFilter::ENFORCE_NO_SEEDING_NO_MIGRATION
+      TrackedPreferenceHelper::ENFORCE_NO_SEEDING_NO_MIGRATION
     },
   };
+  COMPILE_ASSERT(ARRAYSIZE_UNSAFE(kEnforcementLevelMap) ==
+                     (TrackedPreferenceHelper::ENFORCE_ALL -
+                      TrackedPreferenceHelper::NO_ENFORCEMENT),
+                 missing_enforcement_level);
 
   base::FieldTrial* trial =
       base::FieldTrialList::Find(kSettingsEnforcementExperiment);
   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].level_name == group_name)
         return kEnforcementLevelMap[i].level;
     }
   }
   // TODO(gab): Switch default to ENFORCE_ALL when the field trial config is up.
-  return PrefHashFilter::NO_ENFORCEMENT;
+  return TrackedPreferenceHelper::NO_ENFORCEMENT;
 }
 
 // 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 123 matching lines @@
                  pref_io_task_runner,
                  policy_service,
                  managed_user_settings,
                  pref_hash_store.Pass(),
                  extension_prefs,
                  async);
   return factory.CreateSyncable(pref_registry.get());
 }
 
 }  // namespace chrome_prefs