Move migration code out of WebDatabase and into table-specific classes.

chrome/browser/webdata/web_database.cc

 // Copyright (c) 2011 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/webdata/web_database.h"
 
 #include <algorithm>
-#include <limits>
-#include <set>
-#include <string>
 
 #include "app/sql/statement.h"
 #include "app/sql/transaction.h"
-#include "base/string_number_conversions.h"
-#include "chrome/browser/autofill/autofill_country.h"
-#include "chrome/browser/autofill/autofill_profile.h"
-#include "chrome/browser/autofill/autofill_type.h"
-#include "chrome/browser/autofill/personal_data_manager.h"
 #include "chrome/browser/diagnostics/sqlite_diagnostics.h"
-#include "chrome/browser/webdata/autofill_util.h"
-#include "chrome/common/guid.h"
 #include "content/common/notification_service.h"
 
-using base::Time;
-
 namespace {
 
 // Current version number.  Note: when changing the current version number,
 // corresponding changes must happen in the unit tests, and new migration test
 // added.  See |WebDatabaseMigrationTest::kCurrentTestedVersionNumber|.
 const int kCurrentVersionNumber = 36;
 const int kCompatibleVersionNumber = 36;
 
-// TODO(dhollowa): Find a common place for this.  It is duplicated in
-// personal_data_manager.cc.
-template<typename T>
-T* address_of(T& v) {
-  return &v;
-}
-
 }  // anonymous namespace
 
 WebDatabase::WebDatabase() {}
 
 WebDatabase::~WebDatabase() {}
 
 void WebDatabase::BeginTransaction() {
   db_.BeginTransaction();
 }
 
@@ skipping 81 matching lines @@
   // If the file on disk is an older database version, bring it up to date.
   // If the migration fails we return an error to caller and do not commit
   // the migration.
   sql::InitStatus migration_status = MigrateOldVersionsAsNeeded();
   if (migration_status != sql::INIT_OK)
     return migration_status;
 
   return transaction.Commit() ? sql::INIT_OK : sql::INIT_FAILURE;
 }
 
+void WebDatabase::ChangeVersion(int version_num,
+    bool update_compatible_version_num) {
+  meta_table_.SetVersionNumber(version_num);
+  if (update_compatible_version_num) {
+    meta_table_.SetCompatibleVersionNumber(
+          std::min(version_num, kCompatibleVersionNumber));
+  }
+}
+
+sql::InitStatus WebDatabase::FailedMigrationTo(int version_num) {
+  LOG(WARNING) << "Unable to update web database to version "
+               << version_num << ".";
+  NOTREACHED();
+  return sql::INIT_FAILURE;
+}
+
 sql::InitStatus WebDatabase::MigrateOldVersionsAsNeeded() {
   // Migrate if necessary.
   int current_version = meta_table_.GetVersionNumber();
   switch (current_version) {
     // Versions 1 - 19 are unhandled.  Version numbers greater than
     // kCurrentVersionNumber should have already been weeded out by the caller.
     default:
       // When the version is too old, we return failure error code.  The schema
       // is too out of date to migrate.
       // There should not be a released product that makes a database too old to
       // migrate. If we do encounter such a legacy database, we will need a
       // better solution to handle it (i.e., pop up a dialog to tell the user,
       // erase all their prefs and start over, etc.).
       LOG(WARNING) << "Web database version " << current_version <<
           " is too old to handle.";
       NOTREACHED();
       return sql::INIT_FAILURE;
 
     case 20:
-      // Add the autogenerate_keyword column.
-      if (!db_.Execute("ALTER TABLE keywords ADD COLUMN autogenerate_keyword "
-                       "INTEGER DEFAULT 0")) {
-        LOG(WARNING) << "Unable to update web database to version 21.";
-        NOTREACHED();
-        return sql::INIT_FAILURE;
-      }
-      meta_table_.SetVersionNumber(21);
-      meta_table_.SetCompatibleVersionNumber(
-          std::min(21, kCompatibleVersionNumber));
+      if (!keyword_table_->AddAutoGenerateKeywordColumnForVersion21())
+        return FailedMigrationTo(21);
+
+      ChangeVersion(21, true);
       // FALL THROUGH
 
     case 21:
-      if (!autofill_table_->ClearAutofillEmptyValueElements()) {
-        LOG(WARNING) << "Failed to clean-up autofill DB.";
-        NOTREACHED();
-        return sql::INIT_FAILURE;
-      }
-      meta_table_.SetVersionNumber(22);
-      // No change in the compatibility version number.
+      if (!autofill_table_->ClearAutofillEmptyValueElements())
+        return FailedMigrationTo(22);
 
+      ChangeVersion(22, false);
       // FALL THROUGH
 
     case 22:
-      // Add the card_number_encrypted column if credit card table was not
-      // created in this build (otherwise the column already exists).
-      // WARNING: Do not change the order of the execution of the SQL
-      // statements in this case!  Profile corruption and data migration
-      // issues WILL OCCUR. (see http://crbug.com/10913)
-      //
-      // The problem is that if a user has a profile which was created before
-      // r37036, when the credit_cards table was added, and then failed to
-      // update this profile between the credit card addition and the addition
-      // of the "encrypted" columns (44963), the next data migration will put
-      // the user's profile in an incoherent state: The user will update from
-      // a data profile set to be earlier than 22, and therefore pass through
-      // this update case.  But because the user did not have a credit_cards
-      // table before starting Chrome, it will have just been initialized
-      // above, and so already have these columns -- and thus this data
-      // update step will have failed.
-      //
-      // The false assumption in this case is that at this step in the
-      // migration, the user has a credit card table, and that this
-      // table does not include encrypted columns!
-      // Because this case does not roll back the complete set of SQL
-      // transactions properly in case of failure (that is, it does not
-      // roll back the table initialization done above), the incoherent
-      // profile will now see itself as being at version 22 -- but include a
-      // fully initialized credit_cards table.  Every time Chrome runs, it
-      // will try to update the web database and fail at this step, unless
-      // we allow for the faulty assumption described above by checking for
-      // the existence of the columns only AFTER we've executed the commands
-      // to add them.
-      if (!db_.DoesColumnExist("credit_cards", "card_number_encrypted")) {
-        if (!db_.Execute("ALTER TABLE credit_cards ADD COLUMN "
-                         "card_number_encrypted BLOB DEFAULT NULL")) {
-          LOG(WARNING) << "Could not add card_number_encrypted to "
-                          "credit_cards table.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-      }
+      if (!autofill_table_->AddCardNumberEncryptedColumnForVersion23())
+        return FailedMigrationTo(23);
 
-      if (!db_.DoesColumnExist("credit_cards", "verification_code_encrypted")) {
-        if (!db_.Execute("ALTER TABLE credit_cards ADD COLUMN "
-                         "verification_code_encrypted BLOB DEFAULT NULL")) {
-          LOG(WARNING) << "Could not add verification_code_encrypted to "
-                          "credit_cards table.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-      }
-      meta_table_.SetVersionNumber(23);
+      ChangeVersion(23, false);
       // FALL THROUGH
 
-    case 23: {
-      // One-time cleanup for Chromium bug 38364.  In the presence of
-      // multi-byte UTF-8 characters, that bug could cause Autofill strings
-      // to grow larger and more corrupt with each save.  The cleanup removes
-      // any row with a string field larger than a reasonable size.  The string
-      // fields examined here are precisely the ones that were subject to
-      // corruption by the original bug.
-      const std::string autofill_is_too_big =
-          "max(length(name), length(value)) > 500";
+    case 23:
+      if (!autofill_table_->CleanupOversizedStringFieldsForVersion24())
+        return FailedMigrationTo(24);
 
-      const std::string credit_cards_is_too_big =
-          "max(length(label), length(name_on_card), length(type), "
-          "    length(expiration_month), length(expiration_year), "
-          "    length(billing_address), length(shipping_address) "
-          ") > 500";
-
-      const std::string autofill_profiles_is_too_big =
-          "max(length(label), length(first_name), "
-          "    length(middle_name), length(last_name), length(email), "
-          "    length(company_name), length(address_line_1), "
-          "    length(address_line_2), length(city), length(state), "
-          "    length(zipcode), length(country), length(phone), "
-          "    length(fax)) > 500";
-
-      std::string query = "DELETE FROM autofill_dates WHERE pair_id IN ("
-          "SELECT pair_id FROM autofill WHERE " + autofill_is_too_big + ")";
-      if (!db_.Execute(query.c_str())) {
-        LOG(WARNING) << "Unable to update web database to version 24.";
-        NOTREACHED();
-        return sql::INIT_FAILURE;
-      }
-      query = "DELETE FROM autofill WHERE " + autofill_is_too_big;
-      if (!db_.Execute(query.c_str())) {
-        LOG(WARNING) << "Unable to update web database to version 24.";
-        NOTREACHED();
-        return sql::INIT_FAILURE;
-      }
-      // Only delete from legacy credit card tables where specific columns
-      // exist.
-      if (db_.DoesColumnExist("credit_cards", "label") &&
-          db_.DoesColumnExist("credit_cards", "name_on_card") &&
-          db_.DoesColumnExist("credit_cards", "type") &&
-          db_.DoesColumnExist("credit_cards", "expiration_month") &&
-          db_.DoesColumnExist("credit_cards", "expiration_year") &&
-          db_.DoesColumnExist("credit_cards", "billing_address") &&
-          db_.DoesColumnExist("credit_cards", "shipping_address") &&
-          db_.DoesColumnExist("autofill_profiles", "label")) {
-        query = "DELETE FROM credit_cards WHERE (" + credit_cards_is_too_big +
-            ") OR label IN (SELECT label FROM autofill_profiles WHERE " +
-            autofill_profiles_is_too_big + ")";
-        if (!db_.Execute(query.c_str())) {
-          LOG(WARNING) << "Unable to update web database to version 24.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-      }
-      if (db_.DoesColumnExist("autofill_profiles", "label")) {
-        query = "DELETE FROM autofill_profiles WHERE " +
-            autofill_profiles_is_too_big;
-        if (!db_.Execute(query.c_str())) {
-          LOG(WARNING) << "Unable to update web database to version 24.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-      }
-
-      meta_table_.SetVersionNumber(24);
-
+      ChangeVersion(24, false);
       // FALL THROUGH
-    }
 
     case 24:
-      // Add the logo_id column if keyword table was not created in this build.
-      if (!db_.Execute("ALTER TABLE keywords ADD COLUMN logo_id "
-                       "INTEGER DEFAULT 0")) {
-        LOG(WARNING) << "Unable to update web database to version 25.";
-        NOTREACHED();
-        return sql::INIT_FAILURE;
-      }
-      meta_table_.SetVersionNumber(25);
-      meta_table_.SetCompatibleVersionNumber(
-          std::min(25, kCompatibleVersionNumber));
+      if (!keyword_table_->AddLogoIDColumnForVersionVersion25())
+        return FailedMigrationTo(25);
+
+      ChangeVersion(25, true);
       // FALL THROUGH
 
     case 25:
-      // Add the created_by_policy column.
-      if (!db_.Execute("ALTER TABLE keywords ADD COLUMN created_by_policy "
-                       "INTEGER DEFAULT 0")) {
-        LOG(WARNING) << "Unable to update web database to version 26.";
-        NOTREACHED();
-        return sql::INIT_FAILURE;
-      }
+      if (!keyword_table_->AddCreatedByPolicyColumnForVersion26())
+        return FailedMigrationTo(26);
 
-      meta_table_.SetVersionNumber(26);
-      meta_table_.SetCompatibleVersionNumber(
-          std::min(26, kCompatibleVersionNumber));
+      ChangeVersion(26, true);
       // FALL THROUGH
 
-    case 26: {
-      // Only migrate from legacy credit card tables where specific columns
-      // exist.
-      if (db_.DoesColumnExist("credit_cards", "unique_id") &&
-          db_.DoesColumnExist("credit_cards", "billing_address") &&
-          db_.DoesColumnExist("autofill_profiles", "unique_id")) {
-        // Change the credit_cards.billing_address column from a string to an
-        // int.  The stored string is the label of an address, so we have to
-        // select the unique ID of this address using the label as a foreign
-        // key into the |autofill_profiles| table.
-        std::string stmt =
-            "SELECT credit_cards.unique_id, autofill_profiles.unique_id "
-            "FROM autofill_profiles, credit_cards "
-            "WHERE credit_cards.billing_address = autofill_profiles.label";
-        sql::Statement s(db_.GetUniqueStatement(stmt.c_str()));
-        if (!s) {
-          LOG(WARNING) << "Statement prepare failed";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
+    case 26:
+      if (!autofill_table_->UpdateLegacyCreditCardsForVersion27())
+        return FailedMigrationTo(27);
 
-        std::map<int, int> cc_billing_map;
-        while (s.Step())
-          cc_billing_map[s.ColumnInt(0)] = s.ColumnInt(1);
-
-        // Windows already stores the IDs as strings in |billing_address|. Try
-        // to convert those.
-        if (cc_billing_map.empty()) {
-          std::string stmt =
-            "SELECT unique_id,billing_address FROM credit_cards";
-          sql::Statement s(db_.GetUniqueStatement(stmt.c_str()));
-          if (!s) {
-            LOG(WARNING) << "Statement prepare failed";
-            NOTREACHED();
-            return sql::INIT_FAILURE;
-          }
-
-          while (s.Step()) {
-            int id = 0;
-            if (base::StringToInt(s.ColumnString(1), &id))
-              cc_billing_map[s.ColumnInt(0)] = id;
-          }
-        }
-
-        if (!db_.Execute("CREATE TABLE credit_cards_temp ( "
-                         "label VARCHAR, "
-                         "unique_id INTEGER PRIMARY KEY, "
-                         "name_on_card VARCHAR, "
-                         "type VARCHAR, "
-                         "card_number VARCHAR, "
-                         "expiration_month INTEGER, "
-                         "expiration_year INTEGER, "
-                         "verification_code VARCHAR, "
-                         "billing_address INTEGER, "
-                         "shipping_address VARCHAR, "
-                         "card_number_encrypted BLOB, "
-                         "verification_code_encrypted BLOB)")) {
-          LOG(WARNING) << "Unable to update web database to version 27.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        if (!db_.Execute(
-            "INSERT INTO credit_cards_temp "
-            "SELECT label,unique_id,name_on_card,type,card_number,"
-            "expiration_month,expiration_year,verification_code,0,"
-            "shipping_address,card_number_encrypted,"
-            "verification_code_encrypted FROM credit_cards")) {
-          LOG(WARNING) << "Unable to update web database to version 27.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        if (!db_.Execute("DROP TABLE credit_cards")) {
-          LOG(WARNING) << "Unable to update web database to version 27.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        if (!db_.Execute(
-            "ALTER TABLE credit_cards_temp RENAME TO credit_cards")) {
-          LOG(WARNING) << "Unable to update web database to version 27.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        for (std::map<int, int>::const_iterator iter = cc_billing_map.begin();
-             iter != cc_billing_map.end(); ++iter) {
-          sql::Statement s(db_.GetCachedStatement(
-              SQL_FROM_HERE,
-              "UPDATE credit_cards SET billing_address=? WHERE unique_id=?"));
-          if (!s) {
-            LOG(WARNING) << "Statement prepare failed";
-            NOTREACHED();
-            return sql::INIT_FAILURE;
-          }
-
-          s.BindInt(0, (*iter).second);
-          s.BindInt(1, (*iter).first);
-
-          if (!s.Run()) {
-            LOG(WARNING) << "Unable to update web database to version 27.";
-            NOTREACHED();
-            return sql::INIT_FAILURE;
-          }
-        }
-      }
-
-      meta_table_.SetVersionNumber(27);
-      meta_table_.SetCompatibleVersionNumber(
-          std::min(27, kCompatibleVersionNumber));
-
+      ChangeVersion(27, true);
       // FALL THROUGH
-    }
 
     case 27:
-      // Add supports_instant to keywords.
-      if (!db_.Execute("ALTER TABLE keywords ADD COLUMN supports_instant "
-                       "INTEGER DEFAULT 0")) {
-        LOG(WARNING) << "Unable to update web database to version 28.";
-        NOTREACHED();
-        return sql::INIT_FAILURE;
-      }
-      meta_table_.SetVersionNumber(28);
-      meta_table_.SetCompatibleVersionNumber(
-          std::min(28, kCompatibleVersionNumber));
+      if (!keyword_table_->AddSupportsInstantColumnForVersion28())
+        return FailedMigrationTo(28);
 
+      ChangeVersion(28, true);
       // FALL THROUGH
 
     case 28:
-      // Keywords loses the column supports_instant and gets instant_url.
-      if (!db_.Execute("ALTER TABLE keywords ADD COLUMN instant_url "
-                       "VARCHAR")) {
-        LOG(WARNING) << "Unable to update web database to version 29.";
-        NOTREACHED();
-        return sql::INIT_FAILURE;
-      }
-      if (!db_.Execute("CREATE TABLE keywords_temp ("
-                       "id INTEGER PRIMARY KEY,"
-                       "short_name VARCHAR NOT NULL,"
-                       "keyword VARCHAR NOT NULL,"
-                       "favicon_url VARCHAR NOT NULL,"
-                       "url VARCHAR NOT NULL,"
-                       "show_in_default_list INTEGER,"
-                       "safe_for_autoreplace INTEGER,"
-                       "originating_url VARCHAR,"
-                       "date_created INTEGER DEFAULT 0,"
-                       "usage_count INTEGER DEFAULT 0,"
-                       "input_encodings VARCHAR,"
-                       "suggest_url VARCHAR,"
-                       "prepopulate_id INTEGER DEFAULT 0,"
-                       "autogenerate_keyword INTEGER DEFAULT 0,"
-                       "logo_id INTEGER DEFAULT 0,"
-                       "created_by_policy INTEGER DEFAULT 0,"
-                       "instant_url VARCHAR)")) {
-        LOG(WARNING) << "Unable to update web database to version 29.";
-        NOTREACHED();
-        return sql::INIT_FAILURE;
-      }
+      if (!keyword_table_->ChangeInstantUrlToSupportsInstantForVersion29())
+        return FailedMigrationTo(29);
 
-      if (!db_.Execute(
-          "INSERT INTO keywords_temp "
-          "SELECT id, short_name, keyword, favicon_url, url, "
-          "show_in_default_list, safe_for_autoreplace, originating_url, "
-          "date_created, usage_count, input_encodings, suggest_url, "
-          "prepopulate_id, autogenerate_keyword, logo_id, created_by_policy, "
-          "instant_url FROM keywords")) {
-        LOG(WARNING) << "Unable to update web database to version 29.";
-        NOTREACHED();
-        return sql::INIT_FAILURE;
-      }
-
-      if (!db_.Execute("DROP TABLE keywords")) {
-        LOG(WARNING) << "Unable to update web database to version 29.";
-        NOTREACHED();
-        return sql::INIT_FAILURE;
-      }
-
-      if (!db_.Execute(
-          "ALTER TABLE keywords_temp RENAME TO keywords")) {
-        LOG(WARNING) << "Unable to update web database to version 29.";
-        NOTREACHED();
-        return sql::INIT_FAILURE;
-      }
-
-      meta_table_.SetVersionNumber(29);
-      meta_table_.SetCompatibleVersionNumber(
-          std::min(29, kCompatibleVersionNumber));
-
+      ChangeVersion(29, true);
       // FALL THROUGH
 
     case 29:
-      // Add date_modified to autofill_profiles.
-      if (!db_.DoesColumnExist("autofill_profiles", "date_modified")) {
-        if (!db_.Execute("ALTER TABLE autofill_profiles ADD COLUMN "
-                         "date_modified INTEGER NON NULL DEFAULT 0")) {
-          LOG(WARNING) << "Unable to update web database to version 30";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
+      if (!autofill_table_->AddDateModifedForVersion30())
+        return FailedMigrationTo(30);
 
-        sql::Statement s(db_.GetUniqueStatement(
-            "UPDATE autofill_profiles SET date_modified=?"));
-        if (!s) {
-          LOG(WARNING) << "Unable to update web database to version 30.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        s.BindInt64(0, Time::Now().ToTimeT());
-
-        if (!s.Run()) {
-          LOG(WARNING) << "Unable to update web database to version 30.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-      }
-
-      // Add date_modified to credit_cards.
-      if (!db_.DoesColumnExist("credit_cards", "date_modified")) {
-        if (!db_.Execute("ALTER TABLE credit_cards ADD COLUMN "
-                         "date_modified INTEGER NON NULL DEFAULT 0")) {
-          LOG(WARNING) << "Unable to update web database to version 30";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        sql::Statement s(db_.GetUniqueStatement(
-            "UPDATE credit_cards SET date_modified=?"));
-        if (!s) {
-          LOG(WARNING) << "Unable to update web database to version 30.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        s.BindInt64(0, Time::Now().ToTimeT());
-
-        if (!s.Run()) {
-          LOG(WARNING) << "Unable to update web database to version 30.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-      }
-
-      meta_table_.SetVersionNumber(30);
-      meta_table_.SetCompatibleVersionNumber(
-          std::min(30, kCompatibleVersionNumber));
-
+      ChangeVersion(30, true);
       // FALL THROUGH
 
     case 30:
-      // Add |guid| column to |autofill_profiles| table.
-      // Note that we need to check for the guid column's existence due to the
-      // fact that for a version 22 database the |autofill_profiles| table
-      // gets created fresh with |InitAutofillProfilesTable|.
-      if (!db_.DoesColumnExist("autofill_profiles", "guid")) {
-        if (!db_.Execute("ALTER TABLE autofill_profiles ADD COLUMN "
-                         "guid VARCHAR NOT NULL DEFAULT \"\"")) {
-          LOG(WARNING) << "Unable to update web database to version 30.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
+      if (!autofill_table_->AddGUIDToCreditCardsAndProfilesForVersion31())
+        return FailedMigrationTo(31);
 
-        // Set all the |guid| fields to valid values.
-        {
-          sql::Statement s(db_.GetUniqueStatement("SELECT unique_id "
-                                                  "FROM autofill_profiles"));
-
-          if (!s) {
-            LOG(WARNING) << "Unable to update web database to version 30.";
-            NOTREACHED();
-            return sql::INIT_FAILURE;
-          }
-
-          while (s.Step()) {
-            sql::Statement update_s(
-                db_.GetUniqueStatement("UPDATE autofill_profiles "
-                                       "SET guid=? WHERE unique_id=?"));
-            if (!update_s) {
-              LOG(WARNING) << "Unable to update web database to version 30.";
-              NOTREACHED();
-              return sql::INIT_FAILURE;
-            }
-            update_s.BindString(0, guid::GenerateGUID());
-            update_s.BindInt(1, s.ColumnInt(0));
-
-            if (!update_s.Run()) {
-              LOG(WARNING) << "Unable to update web database to version 30.";
-              NOTREACHED();
-              return sql::INIT_FAILURE;
-            }
-          }
-        }
-      }
-
-      // Add |guid| column to |credit_cards| table.
-      // Note that we need to check for the guid column's existence due to the
-      // fact that for a version 22 database the |autofill_profiles| table
-      // gets created fresh with |InitAutofillProfilesTable|.
-      if (!db_.DoesColumnExist("credit_cards", "guid")) {
-        if (!db_.Execute("ALTER TABLE credit_cards ADD COLUMN "
-                         "guid VARCHAR NOT NULL DEFAULT \"\"")) {
-          LOG(WARNING) << "Unable to update web database to version 30.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        // Set all the |guid| fields to valid values.
-        {
-          sql::Statement s(db_.GetUniqueStatement("SELECT unique_id "
-                                                  "FROM credit_cards"));
-          if (!s) {
-            LOG(WARNING) << "Unable to update web database to version 30.";
-            NOTREACHED();
-            return sql::INIT_FAILURE;
-          }
-
-          while (s.Step()) {
-            sql::Statement update_s(
-                db_.GetUniqueStatement("UPDATE credit_cards "
-                                       "set guid=? WHERE unique_id=?"));
-            if (!update_s) {
-              LOG(WARNING) << "Unable to update web database to version 30.";
-              NOTREACHED();
-              return sql::INIT_FAILURE;
-            }
-            update_s.BindString(0, guid::GenerateGUID());
-            update_s.BindInt(1, s.ColumnInt(0));
-
-            if (!update_s.Run()) {
-              LOG(WARNING) << "Unable to update web database to version 30.";
-              NOTREACHED();
-              return sql::INIT_FAILURE;
-            }
-          }
-        }
-      }
-
-      meta_table_.SetVersionNumber(31);
-      meta_table_.SetCompatibleVersionNumber(
-          std::min(31, kCompatibleVersionNumber));
-
+      ChangeVersion(31, true);
       // FALL THROUGH
 
     case 31:
-      if (db_.DoesColumnExist("autofill_profiles", "unique_id")) {
-        if (!db_.Execute("CREATE TABLE autofill_profiles_temp ( "
-                         "guid VARCHAR PRIMARY KEY, "
-                         "label VARCHAR, "
-                         "first_name VARCHAR, "
-                         "middle_name VARCHAR, "
-                         "last_name VARCHAR, "
-                         "email VARCHAR, "
-                         "company_name VARCHAR, "
-                         "address_line_1 VARCHAR, "
-                         "address_line_2 VARCHAR, "
-                         "city VARCHAR, "
-                         "state VARCHAR, "
-                         "zipcode VARCHAR, "
-                         "country VARCHAR, "
-                         "phone VARCHAR, "
-                         "fax VARCHAR, "
-                         "date_modified INTEGER NOT NULL DEFAULT 0)")) {
-          LOG(WARNING) << "Unable to update web database to version 32.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
+      if (!autofill_table_->UpdateProfilesAndCreditCardsForVersion32())
+        return FailedMigrationTo(32);
 
-        if (!db_.Execute(
-            "INSERT INTO autofill_profiles_temp "
-            "SELECT guid, label, first_name, middle_name, last_name, email, "
-            "company_name, address_line_1, address_line_2, city, state, "
-            "zipcode, country, phone, fax, date_modified "
-            "FROM autofill_profiles")) {
-          LOG(WARNING) << "Unable to update web database to version 32.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        if (!db_.Execute("DROP TABLE autofill_profiles")) {
-          LOG(WARNING) << "Unable to update web database to version 32.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        if (!db_.Execute(
-            "ALTER TABLE autofill_profiles_temp RENAME TO autofill_profiles")) {
-          LOG(WARNING) << "Unable to update web database to version 32.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-      }
-
-      if (db_.DoesColumnExist("credit_cards", "unique_id")) {
-        if (!db_.Execute("CREATE TABLE credit_cards_temp ( "
-                         "guid VARCHAR PRIMARY KEY, "
-                         "label VARCHAR, "
-                         "name_on_card VARCHAR, "
-                         "expiration_month INTEGER, "
-                         "expiration_year INTEGER, "
-                         "card_number_encrypted BLOB, "
-                         "date_modified INTEGER NOT NULL DEFAULT 0)")) {
-          LOG(WARNING) << "Unable to update web database to version 32.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        if (!db_.Execute(
-            "INSERT INTO credit_cards_temp "
-            "SELECT guid, label, name_on_card, expiration_month, "
-            "expiration_year, card_number_encrypted, date_modified "
-            "FROM credit_cards")) {
-          LOG(WARNING) << "Unable to update web database to version 32.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        if (!db_.Execute("DROP TABLE credit_cards")) {
-          LOG(WARNING) << "Unable to update web database to version 32.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        if (!db_.Execute(
-            "ALTER TABLE credit_cards_temp RENAME TO credit_cards")) {
-          LOG(WARNING) << "Unable to update web database to version 32.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-      }
-
-      meta_table_.SetVersionNumber(32);
-      meta_table_.SetCompatibleVersionNumber(
-          std::min(32, kCompatibleVersionNumber));
-
+      ChangeVersion(32, true);
       // FALL THROUGH
 
     case 32:
-      // Test the existence of the |first_name| column as an indication that
-      // we need a migration.  It is possible that the new |autofill_profiles|
-      // schema is in place because the table was newly created when migrating
-      // from a pre-version-22 database.
-      if (db_.DoesColumnExist("autofill_profiles", "first_name")) {
-        // Create autofill_profiles_temp table that will receive the data.
-        if (!db_.DoesTableExist("autofill_profiles_temp")) {
-          if (!db_.Execute("CREATE TABLE autofill_profiles_temp ( "
-                           "guid VARCHAR PRIMARY KEY, "
-                           "company_name VARCHAR, "
-                           "address_line_1 VARCHAR, "
-                           "address_line_2 VARCHAR, "
-                           "city VARCHAR, "
-                           "state VARCHAR, "
-                           "zipcode VARCHAR, "
-                           "country VARCHAR, "
-                           "date_modified INTEGER NOT NULL DEFAULT 0)")) {
-            NOTREACHED();
-            return sql::INIT_FAILURE;
-          }
-        }
+      if (!autofill_table_->UpdateProfilesBasedOnFirstNameForVersion33())
+        return FailedMigrationTo(33);
 
-        {
-          sql::Statement s(db_.GetUniqueStatement(
-              "SELECT guid, first_name, middle_name, last_name, email, "
-              "company_name, address_line_1, address_line_2, city, state, "
-              "zipcode, country, phone, fax, date_modified "
-              "FROM autofill_profiles"));
-          while (s.Step()) {
-            AutofillProfile profile;
-            profile.set_guid(s.ColumnString(0));
-            DCHECK(guid::IsValidGUID(profile.guid()));
-
-            profile.SetInfo(NAME_FIRST, s.ColumnString16(1));
-            profile.SetInfo(NAME_MIDDLE, s.ColumnString16(2));
-            profile.SetInfo(NAME_LAST, s.ColumnString16(3));
-            profile.SetInfo(EMAIL_ADDRESS, s.ColumnString16(4));
-            profile.SetInfo(COMPANY_NAME, s.ColumnString16(5));
-            profile.SetInfo(ADDRESS_HOME_LINE1, s.ColumnString16(6));
-            profile.SetInfo(ADDRESS_HOME_LINE2, s.ColumnString16(7));
-            profile.SetInfo(ADDRESS_HOME_CITY, s.ColumnString16(8));
-            profile.SetInfo(ADDRESS_HOME_STATE, s.ColumnString16(9));
-            profile.SetInfo(ADDRESS_HOME_ZIP, s.ColumnString16(10));
-            profile.SetInfo(ADDRESS_HOME_COUNTRY, s.ColumnString16(11));
-            profile.SetInfo(PHONE_HOME_WHOLE_NUMBER, s.ColumnString16(12));
-            profile.SetInfo(PHONE_FAX_WHOLE_NUMBER, s.ColumnString16(13));
-            int64 date_modified = s.ColumnInt64(14);
-
-            sql::Statement s_insert(db_.GetUniqueStatement(
-                "INSERT INTO autofill_profiles_temp"
-                "(guid, company_name, address_line_1, address_line_2, city,"
-                " state, zipcode, country, date_modified)"
-                "VALUES (?,?,?,?,?,?,?,?,?)"));
-            if (!s) {
-              LOG(WARNING) << "Unable to update web database to version 33.";
-              NOTREACHED();
-              return sql::INIT_FAILURE;
-            }
-            s_insert.BindString(0, profile.guid());
-            s_insert.BindString16(1, profile.GetInfo(COMPANY_NAME));
-            s_insert.BindString16(2, profile.GetInfo(ADDRESS_HOME_LINE1));
-            s_insert.BindString16(3, profile.GetInfo(ADDRESS_HOME_LINE2));
-            s_insert.BindString16(4, profile.GetInfo(ADDRESS_HOME_CITY));
-            s_insert.BindString16(5, profile.GetInfo(ADDRESS_HOME_STATE));
-            s_insert.BindString16(6, profile.GetInfo(ADDRESS_HOME_ZIP));
-            s_insert.BindString16(7, profile.GetInfo(ADDRESS_HOME_COUNTRY));
-            s_insert.BindInt64(8, date_modified);
-
-            if (!s_insert.Run()) {
-              NOTREACHED();
-              return sql::INIT_FAILURE;
-            }
-
-            // Add the other bits: names, emails, and phone/fax.
-            if (!autofill_util::AddAutofillProfilePieces(profile, &db_)) {
-              NOTREACHED();
-              return sql::INIT_FAILURE;
-            }
-          }
-        }
-
-        if (!db_.Execute("DROP TABLE autofill_profiles")) {
-          LOG(WARNING) << "Unable to update web database to version 33.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        if (!db_.Execute(
-            "ALTER TABLE autofill_profiles_temp RENAME TO autofill_profiles")) {
-          LOG(WARNING) << "Unable to update web database to version 33.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-      }
-
-      // Remove the labels column from the credit_cards table.
-      if (db_.DoesColumnExist("credit_cards", "label")) {
-        if (!db_.Execute("CREATE TABLE credit_cards_temp ( "
-                         "guid VARCHAR PRIMARY KEY, "
-                         "name_on_card VARCHAR, "
-                         "expiration_month INTEGER, "
-                         "expiration_year INTEGER, "
-                         "card_number_encrypted BLOB, "
-                         "date_modified INTEGER NOT NULL DEFAULT 0)")) {
-          LOG(WARNING) << "Unable to update web database to version 33.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        if (!db_.Execute(
-            "INSERT INTO credit_cards_temp "
-            "SELECT guid, name_on_card, expiration_month, "
-            "expiration_year, card_number_encrypted, date_modified "
-            "FROM credit_cards")) {
-          LOG(WARNING) << "Unable to update web database to version 33.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        if (!db_.Execute("DROP TABLE credit_cards")) {
-          LOG(WARNING) << "Unable to update web database to version 33.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        if (!db_.Execute(
-            "ALTER TABLE credit_cards_temp RENAME TO credit_cards")) {
-          LOG(WARNING) << "Unable to update web database to version 33.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-      }
-
-      meta_table_.SetVersionNumber(33);
-      meta_table_.SetCompatibleVersionNumber(
-          std::min(33, kCompatibleVersionNumber));
-
+      ChangeVersion(33, true);
       // FALL THROUGH
 
     case 33:
-      // Test the existence of the |country_code| column as an indication that
-      // we need a migration.  It is possible that the new |autofill_profiles|
-      // schema is in place because the table was newly created when migrating
-      // from a pre-version-22 database.
-      if (!db_.DoesColumnExist("autofill_profiles", "country_code")) {
-        if (!db_.Execute("ALTER TABLE autofill_profiles ADD COLUMN "
-                         "country_code VARCHAR")) {
-          LOG(WARNING) << "Unable to update web database to version 33.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
+      if (!autofill_table_->UpdatesProfilesBasedOnCountryCodeForVersion34())
+        return FailedMigrationTo(34);
 
-        // Set all the |country_code| fields to match existing |country| values.
-        {
-          sql::Statement s(db_.GetUniqueStatement("SELECT guid, country "
-                                                  "FROM autofill_profiles"));
-
-          if (!s) {
-            LOG(WARNING) << "Unable to update web database to version 33.";
-            NOTREACHED();
-            return sql::INIT_FAILURE;
-          }
-
-          while (s.Step()) {
-            sql::Statement update_s(
-                db_.GetUniqueStatement("UPDATE autofill_profiles "
-                                       "SET country_code=? WHERE guid=?"));
-            if (!update_s) {
-              LOG(WARNING) << "Unable to update web database to version 33.";
-              NOTREACHED();
-              return sql::INIT_FAILURE;
-            }
-            string16 country = s.ColumnString16(1);
-            std::string app_locale = AutofillCountry::ApplicationLocale();
-            update_s.BindString(0, AutofillCountry::GetCountryCode(country,
-                                                                   app_locale));
-            update_s.BindString(1, s.ColumnString(0));
-
-            if (!update_s.Run()) {
-              LOG(WARNING) << "Unable to update web database to version 33.";
-              NOTREACHED();
-              return sql::INIT_FAILURE;
-            }
-          }
-        }
-      }
-
-      meta_table_.SetVersionNumber(34);
-      meta_table_.SetCompatibleVersionNumber(
-          std::min(34, kCompatibleVersionNumber));
-
+      ChangeVersion(34, true);
       // FALL THROUGH
 
     case 34:
-      // Correct all country codes with value "UK" to be "GB".  This data
-      // was mistakenly introduced in build 686.0.  This migration is to clean
-      // it up.  See http://crbug.com/74511 for details.
-      {
-        sql::Statement s(db_.GetUniqueStatement(
-            "UPDATE autofill_profiles SET country_code=\"GB\" "
-            "WHERE country_code=\"UK\""));
+      if (!autofill_table_->CorrectGreatBritainCountryCodesForVersion35())
+        return FailedMigrationTo(35);
 
-        if (!s.Run()) {
-          LOG(WARNING) << "Unable to update web database to version 35.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-      }
-
-      meta_table_.SetVersionNumber(35);
-      meta_table_.SetCompatibleVersionNumber(
-          std::min(35, kCompatibleVersionNumber));
-
+      ChangeVersion(35, true);
       // FALL THROUGH
 
     case 35:
-      // Merge and cull older profiles where possible.
-      {
-        sql::Statement s(db_.GetUniqueStatement(
-            "SELECT guid, date_modified "
-            "FROM autofill_profiles"));
-        if (!s) {
-          NOTREACHED() << "Statement prepare failed";
-          return sql::INIT_FAILURE;
-        }
+      if (!autofill_table_->MergeAndCullOlderProfilesForVersion36())
+        return FailedMigrationTo(36);
 
-        // Accumulate the good profiles.
-        std::vector<AutofillProfile> accumulated_profiles;
-        std::vector<AutofillProfile*> accumulated_profiles_p;
-        std::map<std::string, int64> modification_map;
-        while (s.Step()) {
-          std::string guid = s.ColumnString(0);
-          int64 date_modified = s.ColumnInt64(1);
-          modification_map.insert(
-              std::pair<std::string, int64>(guid, date_modified));
-          AutofillProfile* profile = NULL;
-          if (!autofill_table_->GetAutofillProfile(guid, &profile)) {
-            NOTREACHED() << "Bad read of profile.";
-            return sql::INIT_FAILURE;
-          }
-          scoped_ptr<AutofillProfile> p(profile);
-
-          if (PersonalDataManager::IsValidLearnableProfile(*p)) {
-            std::vector<AutofillProfile> merged_profiles;
-            bool merged = PersonalDataManager::MergeProfile(
-                *p, accumulated_profiles_p, &merged_profiles);
-
-            std::swap(accumulated_profiles, merged_profiles);
-
-            accumulated_profiles_p.clear();
-            accumulated_profiles_p.resize(accumulated_profiles.size());
-            std::transform(accumulated_profiles.begin(),
-                           accumulated_profiles.end(),
-                           accumulated_profiles_p.begin(),
-                           address_of<AutofillProfile>);
-
-            // If the profile got merged trash the original.
-            if (merged)
-              autofill_table_->AddAutofillGUIDToTrash(p->guid());
-          } else {
-            // An invalid profile, so trash it.
-            autofill_table_->AddAutofillGUIDToTrash(p->guid());
-          }
-        }
-
-        // Drop the current profiles.
-        if (!autofill_table_->ClearAutofillProfiles()) {
-          LOG(WARNING) << "Unable to update web database to version 36.";
-          NOTREACHED();
-          return sql::INIT_FAILURE;
-        }
-
-        // Add the newly merged profiles back in.
-        for (std::vector<AutofillProfile>::const_iterator
-                iter = accumulated_profiles.begin();
-             iter != accumulated_profiles.end();
-             ++iter) {
-          if (!autofill_table_->AddAutofillProfile(*iter)) {
-            LOG(WARNING) << "Unable to update web database to version 36.";
-            NOTREACHED();
-            return sql::INIT_FAILURE;
-          }
-
-          // Fix up the original modification date.
-          std::map<std::string, int64>::const_iterator date_item =
-              modification_map.find(iter->guid());
-          if (date_item == modification_map.end()) {
-            LOG(WARNING) << "Unable to update web database to version 36.";
-            NOTREACHED();
-            return sql::INIT_FAILURE;
-          }
-          sql::Statement s_date(db_.GetUniqueStatement(
-              "UPDATE autofill_profiles SET date_modified=? "
-              "WHERE guid=?"));
-          s_date.BindInt64(0, date_item->second);
-          s_date.BindString(1, iter->guid());
-          if (!s_date.Run()) {
-            LOG(WARNING) << "Unable to update web database to version 36.";
-            NOTREACHED();
-            return sql::INIT_FAILURE;
-          }
-        }
-      }
-
-      meta_table_.SetVersionNumber(36);
-      meta_table_.SetCompatibleVersionNumber(
-          std::min(36, kCompatibleVersionNumber));
-
+      ChangeVersion(36, true);
       // FALL THROUGH
 
     // Add successive versions here.  Each should set the version number and
     // compatible version number as appropriate, then fall through to the next
     // case.
 
     case kCurrentVersionNumber:
       // No migration needed.
       return sql::INIT_OK;
   }
 }