Include USB printers in printer list as "provisional" devices.

chrome/browser/ui/webui/print_preview/printer_handler.cc

Index: chrome/browser/ui/webui/print_preview/printer_handler.cc
diff --git a/chrome/browser/ui/webui/print_preview/printer_handler.cc b/chrome/browser/ui/webui/print_preview/printer_handler.cc
deleted file mode 100644
index edc85d18349541b62c707eecb5c2aa50380b763b..0000000000000000000000000000000000000000
--- a/chrome/browser/ui/webui/print_preview/printer_handler.cc
+++ /dev/null
@@ -1,15 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "chrome/browser/ui/webui/print_preview/printer_handler.h"
-
-#include "base/threading/worker_pool.h"
-#include "chrome/browser/ui/webui/print_preview/extension_printer_handler.h"
-
-// static
-scoped_ptr<PrinterHandler> PrinterHandler::CreateForExtensionPrinters(
-    content::BrowserContext* browser_context) {
-  return scoped_ptr<ExtensionPrinterHandler>(new ExtensionPrinterHandler(
-      browser_context, base::WorkerPool::GetTaskRunner(true)));
-}