Use printer id to populate CUPS instead of printer name.

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

 // Copyright (c) 2012 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/print_preview_handler.h"
 
 #include <ctype.h>
 #include <stddef.h>
 
 #include <map>
@@ skipping 365 matching lines @@
     const printing::PrinterBasicInfo& printer) {
 #if defined(OS_MACOSX)
   // On Mac, |printer.printer_description| specifies the printer name and
   // |printer.printer_name| specifies the device name / printer queue name.
   const std::string& real_name = printer.printer_description;
   std::string real_description;
   const auto it = printer.options.find(kDriverNameTagName);
   if (it != printer.options.end())
     real_description = it->second;
   return std::make_pair(real_name, real_description);
+#elif defined(OS_CHROMEOS)
+  // Display the display name.  printer.printer_name contains the name
+  // registered in CUPS which is not human readable.
+  return std::make_pair(printer.printer_display_name,

[xdai1, 2016/10/31 18:08:15]

Where does printer_display_name come from? Seems there is no definition of this
class member?
And also, what is the relationship of the
printing::PrinterBasicInfo::printer_name and chromeos::Printer::id? Are they the
same? And how about printing::PrinterBasicInfo::printer_display_name and
chromeos::Printer::display_name?

[skau, 2016/11/02 22:08:35]

printer_display_name is defined in the dependent patch set.  It's just a string.
 printing::PrinterBasicInfo::printer_display_name and
chromeos::Printer::display_name are equivalent.  PrinterBasicInfo::printer_name
is the name in CUPS so for Chrome OS, that'll be chromeos::Printer::id.  I've
updated the comment to maybe be a little easier to read.

+                        printer.printer_description);
 #else
   return std::make_pair(printer.printer_name, printer.printer_description);
 #endif
 }
 
 void PrintersToValues(const printing::PrinterList& printer_list,
                       base::ListValue* printers) {
   for (const printing::PrinterBasicInfo& printer : printer_list) {
-    std::unique_ptr<base::DictionaryValue> printer_info(
-        new base::DictionaryValue);
+    std::unique_ptr<base::DictionaryValue> printer_info =
+        base::MakeUnique<base::DictionaryValue>();
+    printer_info->SetString(printing::kSettingDeviceName, printer.printer_name);
+
     const auto printer_name_description = GetPrinterNameAndDescription(printer);
     const std::string& printer_name = printer_name_description.first;
     const std::string& printer_description = printer_name_description.second;
-    printer_info->SetString(printing::kSettingDeviceName, printer.printer_name);
     printer_info->SetString(printing::kSettingPrinterName, printer_name);
     printer_info->SetString(printing::kSettingPrinterDescription,
                             printer_description);
 
-    base::DictionaryValue* options = new base::DictionaryValue;
-    printer_info->Set(printing::kSettingPrinterOptions, options);
+    auto options = base::MakeUnique<base::DictionaryValue>();
+    printer_info->Set(printing::kSettingPrinterOptions, std::move(options));
     for (const auto opt_it : printer.options)
       options->SetString(opt_it.first, opt_it.second);
 
     printers->Append(std::move(printer_info));
 
     VLOG(1) << "Found printer " << printer_name << " with device name "
             << printer.printer_name;
   }
 }
 
@@ skipping 1340 matching lines @@
 
 void PrintPreviewHandler::UnregisterForGaiaCookieChanges() {
   if (gaia_cookie_manager_service_)
     gaia_cookie_manager_service_->RemoveObserver(this);
 }
 
 void PrintPreviewHandler::SetPdfSavedClosureForTesting(
     const base::Closure& closure) {
   pdf_file_saved_closure_ = closure;
 }