Make FTS2 inclusion in SQLite optional

sql/sqlite_features_unittest.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 <string>
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "sql/connection.h"
@@ skipping 45 matching lines @@
   std::string sql_text_;
 };
 
 // Do not include fts1 support, it is not useful, and nobody is
 // looking at it.
 TEST_F(SQLiteFeaturesTest, NoFTS1) {
   ASSERT_EQ(SQLITE_ERROR, db().ExecuteAndReturnErrorCode(
       "CREATE VIRTUAL TABLE foo USING fts1(x)"));
 }
 
-#if !defined(OS_IOS)
+#if defined(SQLITE_ENABLE_FTS2)
 // fts2 is used for older history files, so we're signed on for keeping our
-// version up-to-date.  iOS does not include fts2, so this test does not run on
-// iOS.
+// version up-to-date.
 // TODO(shess): Think up a crazy way to get out from having to support
 // this forever.
 TEST_F(SQLiteFeaturesTest, FTS2) {
   ASSERT_TRUE(db().Execute("CREATE VIRTUAL TABLE foo USING fts2(x)"));
 }
 #endif
 
 // fts3 is used for current history files, and also for WebDatabase.
 TEST_F(SQLiteFeaturesTest, FTS3) {
   ASSERT_TRUE(db().Execute("CREATE VIRTUAL TABLE foo USING fts3(x)"));
 }
 
 }  // namespace