Multi-strategy based tracking.

chrome/browser/prefs/tracked_preference.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 "chrome/browser/prefs/tracked_preference.h"
+
+#include "base/metrics/histogram.h"
+
+TrackedPreference::TrackedPreference(size_t reporting_id,
+                                     size_t reporting_ids_count,
+                                     EnforcementLevel enforcement_level)
+    : reporting_id_(reporting_id), reporting_ids_count_(reporting_ids_count),
+      allow_changes_(enforcement_level < ENFORCE),
+      allow_seeding_(enforcement_level < ENFORCE_NO_SEEDING),
+      allow_migration_(enforcement_level < ENFORCE_NO_SEEDING_NO_MIGRATION) {
+}
+
+TrackedPreference::ResetAction TrackedPreference::GetAction(
+    PrefHashStore::ValueState value_state) const {
+  switch (value_state) {
+    case PrefHashStore::UNCHANGED:
+      // Desired case, nothing to do.
+      return DONT_RESET;
+    case PrefHashStore::CLEARED:
+      // Unfortunate case, but there is nothing we can do.
+      return DONT_RESET;
+    case PrefHashStore::TRUSTED_UNKNOWN_VALUE:
+      // It is okay to seed the hash in this case.
+      return DONT_RESET;
+    case PrefHashStore::MIGRATED:
+      return allow_migration_ ? WANTED_RESET : DO_RESET;
+    case PrefHashStore::UNTRUSTED_UNKNOWN_VALUE:
+      return allow_seeding_ ? WANTED_RESET : DO_RESET;
+    case PrefHashStore::CHANGED:
+      return allow_changes_ ? WANTED_RESET : DO_RESET;
+  }
+  NOTREACHED() << "Unexpected PrefHashStore::ValueState: " << value_state;
+  return DONT_RESET;
+}
+
+void TrackedPreference::ReportValidationResult(
+    PrefHashStore::ValueState value_state) const {
+  switch (value_state) {
+    case PrefHashStore::UNCHANGED:
+      UMA_HISTOGRAM_ENUMERATION("Settings.TrackedPreferenceUnchanged",
+                                reporting_id_, reporting_ids_count_);
+      return;
+    case PrefHashStore::CLEARED:
+      UMA_HISTOGRAM_ENUMERATION("Settings.TrackedPreferenceCleared",
+                                reporting_id_, reporting_ids_count_);
+      return;
+    case PrefHashStore::MIGRATED:
+      UMA_HISTOGRAM_ENUMERATION("Settings.TrackedPreferenceMigrated",
+                                reporting_id_, reporting_ids_count_);
+      return;
+    case PrefHashStore::CHANGED:
+      UMA_HISTOGRAM_ENUMERATION("Settings.TrackedPreferenceChanged",
+                                reporting_id_, reporting_ids_count_);
+      return;
+    case PrefHashStore::UNTRUSTED_UNKNOWN_VALUE:
+      UMA_HISTOGRAM_ENUMERATION("Settings.TrackedPreferenceInitialized",
+                                reporting_id_, reporting_ids_count_);
+      return;
+    case PrefHashStore::TRUSTED_UNKNOWN_VALUE:
+      UMA_HISTOGRAM_ENUMERATION("Settings.TrackedPreferenceTrustedInitialized",
+                                reporting_id_, reporting_ids_count_);
+      return;
+  }
+  NOTREACHED() << "Unexpected PrefHashStore::ValueState: " << value_state;
+}
+
+void TrackedPreference::ReportAction(ResetAction reset_action) const {
+  switch (reset_action) {
+    case DONT_RESET:
+      // No report for DONT_RESET.
+      break;
+    case WANTED_RESET:
+      UMA_HISTOGRAM_ENUMERATION("Settings.TrackedPreferenceWantedReset",
+                                reporting_id_, reporting_ids_count_);
+      break;
+    case DO_RESET:
+      UMA_HISTOGRAM_ENUMERATION("Settings.TrackedPreferenceReset",
+                                reporting_id_, reporting_ids_count_);
+      break;
+  }
+}