Remove worker support of Web SQL Database.

LayoutTests/fast/workers/storage/resources/interrupt-database-sync.js

-var db = openDatabaseSync("InterruptDatabaseSyncTest", "1", "", 1);
-db.transaction(function(tx) {
-    tx.executeSql("CREATE TABLE IF NOT EXISTS Test (Foo INT)");
-    var counter = 0;
-    while (true) {
-        // Put both statements on the same line, to make sure the exception is always reported on the same line.
-        tx.executeSql("INSERT INTO Test VALUES (1)"); tx.executeSql("DELETE FROM Test WHERE Foo = 1");
-        if (++counter == 100)
-            postMessage("terminate");
-    }
-});