Bug 1317748 - Make sure to hide the keyboard when scrolling AS panel. (…

…#2246) r=bkmunar

Client/Frontend/Home/ActivityStreamPanel.swift

@@ -67,6 +67,7 @@ class ActivityStreamPanel: UITableViewController, HomePanel {
         tableView.registerClass(AlternateSimpleHighlightCell.self, forCellReuseIdentifier: "HistoryCell")
         tableView.registerClass(ASHorizontalScrollCell.self, forCellReuseIdentifier: "TopSiteCell")
         tableView.backgroundColor = ASPanelUX.backgroundColor
+        tableView.keyboardDismissMode = .OnDrag
         tableView.separatorStyle = .None
         tableView.delegate = self
         tableView.dataSource = self