Remove worker support of Web SQL Database.

LayoutTests/fast/workers/storage/resources/use-same-database-in-page-and-workers.js

-var db = openDatabase("UseSameDatabaseInPageAndWorkers", "", "", 1);
-for (var i = 0; i < 100; i++) {
-    db.transaction(function(tx) {
-        tx.executeSql("INSERT INTO Test VALUES (?)", [i], null,
-                      function(tx, error) { postMessage(error.message); });
-      }, function(error) { postMessage(error.message); },
-      function() { postMessage("transactionSuccessful"); });
-}