Add tests for version migration tesing in for LoginDatabase.

components/test/data/password_manager/login_db_v1.sql

+PRAGMA foreign_keys=OFF;
+BEGIN TRANSACTION;
+CREATE TABLE meta(key LONGVARCHAR NOT NULL UNIQUE PRIMARY KEY, value LONGVARCHAR);
+INSERT INTO "meta" VALUES('last_compatible_version','1');
+INSERT INTO "meta" VALUES('version','1');
+CREATE TABLE logins (
+origin_url VARCHAR NOT NULL,
+action_url VARCHAR,
+username_element VARCHAR,
+username_value VARCHAR,
+password_element VARCHAR,
+password_value BLOB,
+submit_element VARCHAR,
+signon_realm VARCHAR NOT NULL,
+ssl_valid INTEGER NOT NULL,
+preferred INTEGER NOT NULL,
+date_created INTEGER NOT NULL,
+blacklisted_by_user INTEGER NOT NULL,
+scheme INTEGER NOT NULL,
+UNIQUE (origin_url, username_element, username_value, password_element, submit_element, signon_realm));
+INSERT INTO "logins" VALUES(
+'https://accounts.google.com/ServiceLogin', /* origin_url */
+'https://accounts.google.com/ServiceLoginAuth', /* action_url */
+'Email', /* username_element */
+'theerikchen', /* username_value */
+'Passwd', /* password_element */
+X'', /* password_value */
+'', /* submit_element */
+'https://accounts.google.com/', /* signon_realm */
+1, /* ssl_valid */
+1, /* preferred */
+1402955745, /* date_created */
+0, /* blacklisted_by_user */
+0 /* scheme */
+);
+INSERT INTO "logins" VALUES(
+'https://accounts.google.com/ServiceLogin', /* origin_url */
+'https://accounts.google.com/ServiceLoginAuth', /* action_url */
+'Email', /* username_element */
+'theerikchen2', /* username_value */
+'Passwd', /* password_element */
+X'', /* password_value */
+'', /* submit_element */
+'https://accounts.google.com/', /* signon_realm */
+1, /* ssl_valid */
+1, /* preferred */
+1402950000, /* date_created */
+0, /* blacklisted_by_user */
+0 /* scheme */
+);
+CREATE INDEX logins_signon ON logins (signon_realm);
+COMMIT;
+