Return error only if local printer is missing and default caps othervise.

chrome/browser/printing/print_system_task_proxy.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/printing/print_system_task_proxy.h"
 
 #include <ctype.h>
 
 #include <string>
 #include <vector>
@@ skipping 481 matching lines @@
 #endif  // defined(OS_WIN)
 }
 
 
 void PrintSystemTaskProxy::GetPrinterCapabilities(
     const std::string& printer_name) {
   VLOG(1) << "Get printer capabilities start for " << printer_name;
   child_process_logging::ScopedPrinterInfoSetter prn_info(
       print_backend_->GetPrinterDriverInfo(printer_name));
 
+  if (!print_backend_->IsValidPrinter(printer_name)) {
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(&PrintSystemTaskProxy::SendFailedToGetPrinterCapabilities,
+        this, printer_name));
+    return;
+  }
+
   bool set_color_as_default = false;
   bool set_duplex_as_default = false;
   int printer_color_space_for_color = printing::UNKNOWN_COLOR_MODEL;
   int printer_color_space_for_black = printing::UNKNOWN_COLOR_MODEL;
   int default_duplex_setting_value = printing::UNKNOWN_DUPLEX_MODE;
+  bool disable_color_options = false;
 
-  printing::PrinterCapsAndDefaults printer_info;
-  if (!print_backend_->GetPrinterCapsAndDefaults(printer_name,
-                                                 &printer_info) ||
-      !ParsePrinterCapabilities(printer_info,
-                                printer_name,
-                                &set_color_as_default,
-                                &printer_color_space_for_color,
-                                &printer_color_space_for_black,
-                                &set_duplex_as_default,
-                                &default_duplex_setting_value)) {
-    BrowserThread::PostTask(
-        BrowserThread::UI, FROM_HERE,
-        base::Bind(&PrintSystemTaskProxy::SendFailedToGetPrinterCapabilities,
-                   this, printer_name));
-    return;
+  printing::PrinterCapsAndDefaults info;
+  if (print_backend_->GetPrinterCapsAndDefaults(printer_name, &info) &&
+      ParsePrinterCapabilities(info,
+                               printer_name,
+                               &set_color_as_default,
+                               &printer_color_space_for_color,
+                               &printer_color_space_for_black,
+                               &set_duplex_as_default,
+                               &default_duplex_setting_value)) {
+    disable_color_options = (!printer_color_space_for_color ||
+                             !printer_color_space_for_black ||
+                             (printer_color_space_for_color ==
+                              printer_color_space_for_black));
+  } else {
+    VLOG(1) << "Failed to get capabilities for " << printer_name;
   }
-  bool disable_color_options = (!printer_color_space_for_color ||
-                                !printer_color_space_for_black ||
-                                (printer_color_space_for_color ==
-                                 printer_color_space_for_black));
 
   DictionaryValue settings_info;
   settings_info.SetString(kPrinterId, printer_name);
   settings_info.SetBoolean(kDisableColorOption, disable_color_options);
   if (printer_color_space_for_color == printing::UNKNOWN_COLOR_MODEL)
     printer_color_space_for_color = printing::COLOR;
 
   if (printer_color_space_for_black == printing::UNKNOWN_COLOR_MODEL)
     printer_color_space_for_black = printing::GRAY;
 
@@ skipping 17 matching lines @@
   if (handler_)
     handler_->SendPrinterCapabilities(*settings_info);
   delete settings_info;
 }
 
 void PrintSystemTaskProxy::SendFailedToGetPrinterCapabilities(
     const std::string& printer_name) {
   if (handler_)
     handler_->SendFailedToGetPrinterCapabilities(printer_name);
 }