Implement basic USB setup in the cups printer detector. Factor out

chrome/browser/chromeos/printing/printer_configurer.h

 // Copyright 2017 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 CHROME_BROWSER_CHROMEOS_PRINTING_PRINTER_CONFIGURER_H_
 #define CHROME_BROWSER_CHROMEOS_PRINTING_PRINTER_CONFIGURER_H_
 
 #include <memory>
 
 #include "base/callback_forward.h"
 #include "chromeos/printing/printer_configuration.h"
 
 class Profile;
 
 namespace chromeos {
 
-enum SetupResult {
+enum PrinterSetupResult {

[stevenjb, 2017/03/17 17:34:11]

Thank you for the less generic name :) It would be even better if we could scope
this in a class somewhere (or namespace all of this; the repository has 47 files
with the name 'printer' in them).

[Carlson, 2017/03/17 18:47:34]

I think this will take some thought about what makes sense in the larger context
w.r.t. other symbols as well, and will be a part of the crbug/702710 cleanup.

   UNKNOWN,
   FATAL_ERROR,
   SUCCESS,              // Printer set up successfully
   PRINTER_UNREACHABLE,  // Could not reach printer
   DBUS_ERROR,           // Could not contact debugd
 
   // PPD errors
   PPD_TOO_LARGE,     // PPD exceeds size limit
   INVALID_PPD,       // PPD rejected by cupstestppd
   PPD_NOT_FOUND,     // Could not find PPD
   PPD_UNRETRIEVABLE  // Could not download PPD
 };
 
-using PrinterSetupCallback = base::Callback<void(SetupResult)>;
+using PrinterSetupCallback = base::Callback<void(PrinterSetupResult)>;
 
 // Configures printers by retrieving PPDs and registering the printer with CUPS.
 // Class must be constructed and used on the UI thread.
 class PrinterConfigurer {
  public:
   static std::unique_ptr<PrinterConfigurer> Create(Profile* profile);
 
   PrinterConfigurer(const PrinterConfigurer&) = delete;
   PrinterConfigurer& operator=(const PrinterConfigurer&) = delete;
 
   virtual ~PrinterConfigurer() = default;
 
   // Set up |printer| retrieving the appropriate PPD and registering the printer
   // with CUPS.  |callback| is called with the result of the operation.  This
   // method must be called on the UI thread and will run |callback| on the
   // UI thread.
   virtual void SetUpPrinter(const Printer& printer,
                             const PrinterSetupCallback& callback) = 0;
 
  protected:
   PrinterConfigurer() = default;
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_PRINTING_PRINTER_CONFIGURER_H_