Clean up old legacy preference migration logic.

components/user_prefs/tracked/tracked_preferences_migration_unittest.cc

Index: components/user_prefs/tracked/tracked_preferences_migration_unittest.cc
diff --git a/components/user_prefs/tracked/tracked_preferences_migration_unittest.cc b/components/user_prefs/tracked/tracked_preferences_migration_unittest.cc
index 534ee21cd47d26da40a2e5b7b53910555509d0b2..5efb539ffcaa7c1628dd72d0cd55968b89a303ea 100644
--- a/components/user_prefs/tracked/tracked_preferences_migration_unittest.cc
+++ b/components/user_prefs/tracked/tracked_preferences_migration_unittest.cc
@@ -22,7 +22,6 @@
 #include "components/user_prefs/tracked/pref_hash_store.h"
 #include "components/user_prefs/tracked/pref_hash_store_impl.h"
 #include "components/user_prefs/tracked/pref_hash_store_transaction.h"
-#include "components/user_prefs/tracked/pref_service_hash_store_contents.h"
 #include "components/user_prefs/tracked/tracked_preferences_migration.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -87,7 +86,6 @@ class TrackedPreferencesMigrationTest : public testing::Test {
         protected_store_migration_complete_(false) {}
 
   void SetUp() override {
-    PrefServiceHashStoreContents::RegisterPrefs(local_state_.registry());
     Reset();
   }
 
@@ -123,9 +121,6 @@ class TrackedPreferencesMigrationTest : public testing::Test {
             new PrefHashStoreImpl(kSeed, kDeviceId, false)),
         std::unique_ptr<PrefHashStore>(
             new PrefHashStoreImpl(kSeed, kDeviceId, true)),
-        std::unique_ptr<HashStoreContents>(
-            new PrefServiceHashStoreContents(kHashStoreId, &local_state_)),
-
         &mock_unprotected_pref_filter_, &mock_protected_pref_filter_);
 
     // Verify initial expectations are met.
@@ -147,16 +142,6 @@ class TrackedPreferencesMigrationTest : public testing::Test {
     PresetStoreValueHash(store_id, key, value);
   }
 
-  // Sets |key| to |value| in the test store identified by |store_id| before
-  // migration begins. Stores the value hash in Local State as in M36 and
-  // earlier.
-  void PresetLegacyStoreValue(MockPrefStoreID store_id,
-                              const std::string& key,
-                              const std::string value) {
-    PresetStoreValueOnly(store_id, key, value);
-    PresetLegacyValueHash(key, value);
-  }
-
   // Stores a hash for |key| and |value| in the hash store identified by
   // |store_id| before migration begins.
   void PresetStoreValueHash(MockPrefStoreID store_id,
@@ -183,20 +168,6 @@ class TrackedPreferencesMigrationTest : public testing::Test {
         ->StoreHash(key, &string_value);
   }
 
-  // Stores a hash for |key| and |value| in the legacy hash store in
-  // local_state.
-  void PresetLegacyValueHash(const std::string& key,
-                             const std::string value) {
-    std::unique_ptr<PrefHashStore> pref_hash_store(
-        new PrefHashStoreImpl(kSeed, kDeviceId, true));
-
-    base::StringValue string_value(value);
-    PrefHashStoreImpl(kSeed, kDeviceId, true)
-        .BeginTransaction(std::unique_ptr<HashStoreContents>(
-            new PrefServiceHashStoreContents(kHashStoreId, &local_state_)))
-        ->StoreHash(key, &string_value);
-  }
-
   // Returns true if the store opposite to |store_id| is observed for its next
   // successful write.
   bool WasOnSuccessfulWriteCallbackRegistered(MockPrefStoreID store_id) {
@@ -255,16 +226,6 @@ class TrackedPreferencesMigrationTest : public testing::Test {
                                           static_cast<std::string*>(NULL));
   }
 
-  // Determines whether |expected_pref_in_hash_store| has a hash in the Local
-  // State hash store.
-  bool ContainsLegacyHash(const std::string& expected_pref_in_hash_store) {
-    const base::DictionaryValue* hash_store_contents =
-        PrefServiceHashStoreContents(kHashStoreId, &local_state_).GetContents();
-    return hash_store_contents &&
-           hash_store_contents->GetString(expected_pref_in_hash_store,
-                                          static_cast<std::string*>(NULL));
-  }
-
   // Both stores need to hand their prefs over in order for migration to kick
   // in.
   void HandPrefsToMigrator(MockPrefStoreID store_id) {
@@ -482,208 +443,6 @@ TEST_F(TrackedPreferencesMigrationTest, NoMigrationRequired) {
   EXPECT_FALSE(ContainsHash(MOCK_PROTECTED_PREF_STORE, kUnprotectedPref));
 }
 
-TEST_F(TrackedPreferencesMigrationTest, LegacyHashMigrationOnly) {
-  PresetLegacyStoreValue(
-      MOCK_UNPROTECTED_PREF_STORE, kUnprotectedPref, kUnprotectedPrefValue);
-  PresetLegacyStoreValue(
-      MOCK_PROTECTED_PREF_STORE, kProtectedPref, kProtectedPrefValue);
-
-  EXPECT_FALSE(ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kUnprotectedPref));
-  EXPECT_FALSE(ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kProtectedPref));
-
-  EXPECT_FALSE(ContainsHash(MOCK_PROTECTED_PREF_STORE, kProtectedPref));
-  EXPECT_FALSE(ContainsHash(MOCK_PROTECTED_PREF_STORE, kUnprotectedPref));
-
-  EXPECT_TRUE(ContainsLegacyHash(kProtectedPref));
-  EXPECT_TRUE(ContainsLegacyHash(kUnprotectedPref));
-
-  // Hand unprotected prefs to the migrator which should wait for the protected
-  // prefs.
-  HandPrefsToMigrator(MOCK_UNPROTECTED_PREF_STORE);
-  EXPECT_FALSE(HasPrefs(MOCK_UNPROTECTED_PREF_STORE));
-  EXPECT_TRUE(HasPrefs(MOCK_PROTECTED_PREF_STORE));
-  EXPECT_FALSE(MigrationCompleted());
-
-  // Hand protected prefs to the migrator which should proceed with the
-  // migration synchronously.
-  HandPrefsToMigrator(MOCK_PROTECTED_PREF_STORE);
-  EXPECT_TRUE(MigrationCompleted());
-
-  // Prefs should have been handed back over.
-  EXPECT_TRUE(HasPrefs(MOCK_UNPROTECTED_PREF_STORE));
-  EXPECT_TRUE(HasPrefs(MOCK_PROTECTED_PREF_STORE));
-
-  // There is no pending cleanup task for the modern hash stores.
-  EXPECT_FALSE(
-      WasOnSuccessfulWriteCallbackRegistered(MOCK_UNPROTECTED_PREF_STORE));
-  EXPECT_FALSE(
-      WasOnSuccessfulWriteCallbackRegistered(MOCK_PROTECTED_PREF_STORE));
-
-  // Both stores were modified as hashes were moved from Local State.
-  EXPECT_TRUE(StoreModifiedByMigration(MOCK_UNPROTECTED_PREF_STORE));
-  EXPECT_TRUE(StoreModifiedByMigration(MOCK_PROTECTED_PREF_STORE));
-
-  base::StringPairs expected_unprotected_values;
-  expected_unprotected_values.push_back(
-      std::make_pair(kUnprotectedPref, kUnprotectedPrefValue));
-  VerifyValuesStored(MOCK_UNPROTECTED_PREF_STORE, expected_unprotected_values);
-
-  base::StringPairs expected_protected_values;
-  expected_protected_values.push_back(
-      std::make_pair(kProtectedPref, kProtectedPrefValue));
-  VerifyValuesStored(MOCK_PROTECTED_PREF_STORE, expected_protected_values);
-
-  EXPECT_TRUE(ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kUnprotectedPref));
-  EXPECT_FALSE(ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kProtectedPref));
-
-  EXPECT_TRUE(ContainsHash(MOCK_PROTECTED_PREF_STORE, kProtectedPref));
-  EXPECT_FALSE(ContainsHash(MOCK_PROTECTED_PREF_STORE, kUnprotectedPref));
-
-  // The Local State hash store will not be reset until the next run.
-  EXPECT_TRUE(ContainsLegacyHash(kProtectedPref));
-  EXPECT_TRUE(ContainsLegacyHash(kUnprotectedPref));
-
-  Reset();
-
-  HandPrefsToMigrator(MOCK_UNPROTECTED_PREF_STORE);
-  HandPrefsToMigrator(MOCK_PROTECTED_PREF_STORE);
-  EXPECT_TRUE(MigrationCompleted());
-
-  // Neither store was modified.
-  EXPECT_FALSE(StoreModifiedByMigration(MOCK_UNPROTECTED_PREF_STORE));
-  EXPECT_FALSE(StoreModifiedByMigration(MOCK_PROTECTED_PREF_STORE));
-
-  EXPECT_TRUE(ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kUnprotectedPref));
-  EXPECT_FALSE(ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kProtectedPref));
-
-  EXPECT_TRUE(ContainsHash(MOCK_PROTECTED_PREF_STORE, kProtectedPref));
-  EXPECT_FALSE(ContainsHash(MOCK_PROTECTED_PREF_STORE, kUnprotectedPref));
-
-  EXPECT_FALSE(ContainsLegacyHash(kProtectedPref));
-  EXPECT_FALSE(ContainsLegacyHash(kUnprotectedPref));
-}
-
-TEST_F(TrackedPreferencesMigrationTest, FullMigrationWithLegacyHashStore) {
-  // Store some values with matching MACs in Local State.
-  PresetLegacyStoreValue(
-      MOCK_UNPROTECTED_PREF_STORE, kUnprotectedPref, kUnprotectedPrefValue);
-  PresetLegacyStoreValue(MOCK_UNPROTECTED_PREF_STORE,
-                         kPreviouslyUnprotectedPref,
-                         kPreviouslyUnprotectedPrefValue);
-  PresetLegacyStoreValue(
-      MOCK_PROTECTED_PREF_STORE, kProtectedPref, kProtectedPrefValue);
-  PresetLegacyStoreValue(MOCK_PROTECTED_PREF_STORE,
-                         kPreviouslyProtectedPref,
-                         kPreviouslyProtectedPrefValue);
-
-  // Verify that there are no MACs in Preferences or Secure Preferences.
-  EXPECT_FALSE(ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kUnprotectedPref));
-  EXPECT_FALSE(
-      ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kPreviouslyUnprotectedPref));
-  EXPECT_FALSE(ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kProtectedPref));
-  EXPECT_FALSE(
-      ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kPreviouslyProtectedPref));
-
-  EXPECT_FALSE(ContainsHash(MOCK_PROTECTED_PREF_STORE, kUnprotectedPref));
-  EXPECT_FALSE(
-      ContainsHash(MOCK_PROTECTED_PREF_STORE, kPreviouslyUnprotectedPref));
-  EXPECT_FALSE(ContainsHash(MOCK_PROTECTED_PREF_STORE, kProtectedPref));
-  EXPECT_FALSE(
-      ContainsHash(MOCK_PROTECTED_PREF_STORE, kPreviouslyProtectedPref));
-
-  // Verify that there are MACs in Local State.
-  EXPECT_TRUE(ContainsLegacyHash(kUnprotectedPref));
-  EXPECT_TRUE(ContainsLegacyHash(kPreviouslyUnprotectedPref));
-  EXPECT_TRUE(ContainsLegacyHash(kProtectedPref));
-  EXPECT_TRUE(ContainsLegacyHash(kPreviouslyProtectedPref));
-
-  // Perform a first-pass migration.
-  HandPrefsToMigrator(MOCK_UNPROTECTED_PREF_STORE);
-  HandPrefsToMigrator(MOCK_PROTECTED_PREF_STORE);
-  EXPECT_TRUE(MigrationCompleted());
-
-  // All values should have been moved to their preferred locations, including
-  // MACs.
-  base::StringPairs expected_unprotected_values;
-  expected_unprotected_values.push_back(
-      std::make_pair(kUnprotectedPref, kUnprotectedPrefValue));
-  expected_unprotected_values.push_back(
-      std::make_pair(kPreviouslyProtectedPref, kPreviouslyProtectedPrefValue));
-  base::StringPairs expected_protected_values;
-  expected_protected_values.push_back(
-      std::make_pair(kProtectedPref, kProtectedPrefValue));
-  expected_protected_values.push_back(std::make_pair(
-      kPreviouslyUnprotectedPref, kPreviouslyUnprotectedPrefValue));
-
-  VerifyValuesStored(MOCK_UNPROTECTED_PREF_STORE, expected_unprotected_values);
-  VerifyValuesStored(MOCK_PROTECTED_PREF_STORE, expected_protected_values);
-
-  EXPECT_TRUE(ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kUnprotectedPref));
-  EXPECT_TRUE(
-      ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kPreviouslyProtectedPref));
-  EXPECT_TRUE(
-      ContainsHash(MOCK_PROTECTED_PREF_STORE, kPreviouslyUnprotectedPref));
-  EXPECT_TRUE(ContainsHash(MOCK_PROTECTED_PREF_STORE, kProtectedPref));
-
-  EXPECT_FALSE(ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kProtectedPref));
-  EXPECT_FALSE(ContainsHash(MOCK_PROTECTED_PREF_STORE, kUnprotectedPref));
-
-  EXPECT_FALSE(
-      ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kPreviouslyUnprotectedPref));
-  EXPECT_FALSE(
-      ContainsHash(MOCK_PROTECTED_PREF_STORE, kPreviouslyProtectedPref));
-
-  // Removing the values from their previous locations is deferred until the new
-  // locations are persisted.
-  EXPECT_TRUE(ContainsLegacyHash(kUnprotectedPref));
-  EXPECT_TRUE(ContainsLegacyHash(kPreviouslyUnprotectedPref));
-  EXPECT_TRUE(ContainsLegacyHash(kProtectedPref));
-  EXPECT_TRUE(ContainsLegacyHash(kPreviouslyProtectedPref));
-
-  EXPECT_TRUE(
-      WasOnSuccessfulWriteCallbackRegistered(MOCK_UNPROTECTED_PREF_STORE));
-  EXPECT_TRUE(
-      WasOnSuccessfulWriteCallbackRegistered(MOCK_PROTECTED_PREF_STORE));
-
-  SimulateSuccessfulWrite(MOCK_UNPROTECTED_PREF_STORE);
-  SimulateSuccessfulWrite(MOCK_PROTECTED_PREF_STORE);
-
-  Reset();
-
-  HandPrefsToMigrator(MOCK_UNPROTECTED_PREF_STORE);
-  HandPrefsToMigrator(MOCK_PROTECTED_PREF_STORE);
-  EXPECT_TRUE(MigrationCompleted());
-
-  // In this run the MACs should have been removed from their previous
-  // locations. There is no more pending action.
-  EXPECT_FALSE(
-      WasOnSuccessfulWriteCallbackRegistered(MOCK_UNPROTECTED_PREF_STORE));
-  EXPECT_FALSE(
-      WasOnSuccessfulWriteCallbackRegistered(MOCK_PROTECTED_PREF_STORE));
-
-  EXPECT_TRUE(ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kUnprotectedPref));
-  EXPECT_FALSE(
-      ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kPreviouslyUnprotectedPref));
-  EXPECT_FALSE(ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kProtectedPref));
-  EXPECT_TRUE(
-      ContainsHash(MOCK_UNPROTECTED_PREF_STORE, kPreviouslyProtectedPref));
-
-  EXPECT_FALSE(ContainsHash(MOCK_PROTECTED_PREF_STORE, kUnprotectedPref));
-  EXPECT_TRUE(
-      ContainsHash(MOCK_PROTECTED_PREF_STORE, kPreviouslyUnprotectedPref));
-  EXPECT_TRUE(ContainsHash(MOCK_PROTECTED_PREF_STORE, kProtectedPref));
-  EXPECT_FALSE(
-      ContainsHash(MOCK_PROTECTED_PREF_STORE, kPreviouslyProtectedPref));
-
-  EXPECT_FALSE(ContainsLegacyHash(kUnprotectedPref));
-  EXPECT_FALSE(ContainsLegacyHash(kPreviouslyUnprotectedPref));
-  EXPECT_FALSE(ContainsLegacyHash(kProtectedPref));
-  EXPECT_FALSE(ContainsLegacyHash(kPreviouslyProtectedPref));
-
-  VerifyValuesStored(MOCK_UNPROTECTED_PREF_STORE, expected_unprotected_values);
-  VerifyValuesStored(MOCK_PROTECTED_PREF_STORE, expected_protected_values);
-}
-
 TEST_F(TrackedPreferencesMigrationTest, FullMigration) {
   PresetStoreValue(
       MOCK_UNPROTECTED_PREF_STORE, kUnprotectedPref, kUnprotectedPrefValue);