Make CUPS cloud print proxy to support multiple print servers....

chrome/service/cloud_print/printer_job_handler.cc

 // Copyright (c) 2010 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/service/cloud_print/printer_job_handler.h"
 
 #include "base/file_util.h"
 #include "base/json/json_reader.h"
 #include "base/md5.h"
 #include "base/string_util.h"
@@ skipping 27 matching lines @@
       job_handler_message_loop_proxy_(
           base::MessageLoopProxy::CreateForCurrentThread()),
       shutting_down_(false),
       server_job_available_(false),
       printer_update_pending_(true),
       printer_delete_pending_(false),
       task_in_progress_(false) {
 }
 
 bool PrinterJobHandler::Initialize() {
-  if (print_system_->GetPrintBackend()->IsValidPrinter(
+  if (print_system_->IsValidPrinter(
       printer_info_.printer_name)) {
     printer_watcher_ = print_system_->CreatePrinterWatcher(
         printer_info_.printer_name);
     printer_watcher_->StartWatching(this);
     NotifyJobAvailable();
   } else {
     // This printer does not exist any more. Delete it from the server.
     OnPrinterDeleted();
   }
   return true;
@@ skipping 79 matching lines @@
   VLOG(1) << "CP_PROXY: Update printer info, id: "
           << printer_info_cloud_.printer_id;
   // We need to update the parts of the printer info that have changed
   // (could be printer name, description, status or capabilities).
   printing::PrinterBasicInfo printer_info;
   printer_watcher_->GetCurrentPrinterInfo(&printer_info);
   printing::PrinterCapsAndDefaults printer_caps;
   std::string post_data;
   std::string mime_boundary;
   CloudPrintHelpers::CreateMimeBoundaryForUpload(&mime_boundary);
-  if (print_system_->GetPrintBackend()->GetPrinterCapsAndDefaults(
+  if (print_system_->GetPrinterCapsAndDefaults(
       printer_info.printer_name, &printer_caps)) {
     std::string caps_hash = MD5String(printer_caps.printer_capabilities);
     if (caps_hash != printer_info_cloud_.caps_hash) {
       // Hashes don't match, we need to upload new capabilities (the defaults
       // go for free along with the capabilities)
       printer_info_cloud_.caps_hash = caps_hash;
       CloudPrintHelpers::AddMultipartValueForUpload(
           kPrinterCapsValue, printer_caps.printer_capabilities,
           mime_boundary, printer_caps.caps_mime_type, &post_data);
       CloudPrintHelpers::AddMultipartValueForUpload(
@@ skipping 416 matching lines @@
 }
 
 void PrinterJobHandler::OnJobSpoolFailed() {
   DCHECK(MessageLoop::current() == print_thread_.message_loop());
   job_spooler_ = NULL;
   job_handler_message_loop_proxy_->PostTask(FROM_HERE,
                                             NewRunnableMethod(this,
                                                 &PrinterJobHandler::JobFailed,
                                                 PRINT_FAILED));
 }