Remove worker support of Web SQL Database.

LayoutTests/fast/workers/storage/resources/multiple-transactions-on-different-handles-sync.js

-function runTransaction(db)
-{
-    db.transaction(function(tx) {
-       // Execute a read-only statement
-       tx.executeSql("SELECT COUNT(*) FROM Test;");
-
-       // Execute a write statement to make sure SQLite tries to acquire an exclusive lock on the DB file
-       tx.executeSql("INSERT INTO Test VALUES (?);", [1]);
-    });
-}
-
-var db1 = openDatabaseSync("MultipleTransactionsOnDifferentHandlesTest", "1.0",
-                           "Test transactions on different handles to the same DB.", 1);
-db1.transaction(function(tx) {
-    tx.executeSql("CREATE TABLE IF NOT EXISTS Test (Foo int);");
-});
-
-var db2 = openDatabaseSync("MultipleTransactionsOnDifferentHandlesTest", "1.0",
-                           "Test transactions on different handles to the same DB.", 1);
-if (db1 == db2)
-    postMessage("FAIL: db1 == db2");
-else {
-    try {
-        runTransaction(db1);
-        runTransaction(db2);
-        postMessage("PASS");
-    } catch (err) {
-        postMessage("FAIL: " + err);
-    }
-}
-
-postMessage("done");