Convert PpdCache and PpdProvider to TaskScheduler.

chromeos/printing/ppd_provider.h

 // Copyright 2016 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.
 
 #ifndef CHROMEOS_PRINTING_PPD_PROVIDER_H_
 #define CHROMEOS_PRINTING_PPD_PROVIDER_H_
 
 #include <map>
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/files/file_path.h"
-#include "base/sequenced_task_runner.h"
 #include "chromeos/chromeos_export.h"
 #include "chromeos/printing/printer_configuration.h"
 
 namespace net {
 class URLRequestContextGetter;
 }
 
 namespace chromeos {
 namespace printing {
 
@@ skipping 58 matching lines @@
   // NOT_FOUND means we don't know about this Usb device.
   using ResolveUsbIdsCallback =
       base::Callback<void(CallbackResultCode, const std::string&)>;
 
   // Create and return a new PpdProvider with the given cache and options.
   // A references to |url_context_getter| is taken.
   static scoped_refptr<PpdProvider> Create(
       const std::string& browser_locale,
       scoped_refptr<net::URLRequestContextGetter> url_context_getter,
       scoped_refptr<PpdCache> cache,
-      scoped_refptr<base::SequencedTaskRunner> disk_task_runner,
       const Options& options = Options());
 
   // Get all manufacturers for which we have drivers.  Keys of the map will be
   // localized in the default browser locale or the closest available fallback.
   //
   // |cb| will be called on the invoking thread, and will be sequenced.
   virtual void ResolveManufacturers(const ResolveManufacturersCallback& cb) = 0;
 
   // Get all models from a given manufacturer, localized in the default browser
   // locale or the closest available fallback.  |manufacturer| must be a value
@@ skipping 35 matching lines @@
 
  protected:
   friend class base::RefCounted<PpdProvider>;
   virtual ~PpdProvider() {}
 };
 
 }  // namespace printing
 }  // namespace chromeos
 
 #endif  // CHROMEOS_PRINTING_PPD_PROVIDER_H_