Remove worker support of Web SQL Database.

LayoutTests/fast/workers/storage/resources/open-database-set-empty-version-sync.js

-var db = openDatabaseSync("OpenDatabaseSetEmptyVersionTest", "", "Test that the DB version is set to the empty string.", 1);
-
-try {
-    var db2 = openDatabaseSync("OpenDatabaseSetEmptyVersionTest", "test", "Test that the DB version is set to the empty string.", 1);
-    postMessage("FAIL: An exception should've been thrown.");
-} catch (err) {
-    postMessage("PASS");
-}
-postMessage("done");