Check Firewall state only initializing mDns from PrintPreview.

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 <map>
 #include <string>
@@ skipping 620 matching lines @@
   BrowserThread::PostTaskAndReply(
       BrowserThread::FILE, FROM_HERE,
       base::Bind(&EnumeratePrintersOnFileThread,
                  base::Unretained(results)),
       base::Bind(&PrintPreviewHandler::SetupPrinterList,
                  weak_factory_.GetWeakPtr(),
                  base::Owned(results)));
 }
 
 void PrintPreviewHandler::HandleGetPrivetPrinters(const base::ListValue* args) {
+  if (!PrivetPrintingEnabled())
+    return web_ui()->CallJavascriptFunction("onPrivetPrinterSearchDone");
 #if defined(ENABLE_SERVICE_DISCOVERY)
-  if (PrivetPrintingEnabled()) {
-    Profile* profile = Profile::FromWebUI(web_ui());
-    service_discovery_client_ =
-        local_discovery::ServiceDiscoverySharedClient::GetInstance();
-    printer_lister_.reset(new local_discovery::PrivetLocalPrinterLister(
-        service_discovery_client_.get(),
-        profile->GetRequestContext(),
-        this));
-    printer_lister_->Start();
-  }
-#endif
-
-  if (!PrivetPrintingEnabled()) {
-    web_ui()->CallJavascriptFunction("onPrivetPrinterSearchDone");
-  }
+  local_discovery::ServiceDiscoverySharedClient::GetInstanceWithoutAlert(
+      base::Bind(&PrintPreviewHandler::StartPrivetLister,
+                 weak_factory_.GetWeakPtr()));
+#endif  // ENABLE_SERVICE_DISCOVERY
 }
 
 void PrintPreviewHandler::HandleStopGetPrivetPrinters(
     const base::ListValue* args) {
 #if defined(ENABLE_SERVICE_DISCOVERY)
-  if (PrivetPrintingEnabled()) {
+  if (PrivetPrintingEnabled() && printer_lister_) {
     printer_lister_->Stop();
   }
 #endif
 }
 
 void PrintPreviewHandler::HandleGetPrivetPrinterCapabilities(
     const base::ListValue* args) {
 #if defined(ENABLE_SERVICE_DISCOVERY)
   std::string name;
   bool success = args->GetString(0, &name);
@@ skipping 684 matching lines @@
     return false;
   }
   DCHECK(tmp_data->size() && tmp_data->front());
 
   *data = tmp_data;
   *title = print_preview_ui->initiator_title();
   return true;
 }
 
 #if defined(ENABLE_SERVICE_DISCOVERY)
+
+void PrintPreviewHandler::StartPrivetLister(
+    scoped_refptr<local_discovery::ServiceDiscoverySharedClient> client) {
+  if (!PrivetPrintingEnabled())
+    return web_ui()->CallJavascriptFunction("onPrivetPrinterSearchDone");
+
+  Profile* profile = Profile::FromWebUI(web_ui());
+  DCHECK(!service_discovery_client_ || service_discovery_client_ == client);
+  service_discovery_client_ = client;
+  printer_lister_.reset(new local_discovery::PrivetLocalPrinterLister(
+      service_discovery_client_.get(), profile->GetRequestContext(), this));
+  printer_lister_->Start();
+}
+
 void PrintPreviewHandler::LocalPrinterChanged(
     bool added,
     const std::string& name,
     bool has_local_printing,
     const local_discovery::DeviceDescription& description) {
   base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   if (has_local_printing ||
       command_line->HasSwitch(switches::kEnablePrintPreviewRegisterPromos)) {
     base::DictionaryValue info;
     FillPrinterDescription(name, description, has_local_printing, &info);
@@ skipping 80 matching lines @@
   }
 
   privet_local_print_operation_->Start();
 }
 
 
 void PrintPreviewHandler::OnPrivetCapabilities(
     const base::DictionaryValue* capabilities) {
   std::string name = privet_capabilities_operation_->GetHTTPClient()->GetName();
 
-  if (!capabilities || capabilities->HasKey(local_discovery::kPrivetKeyError)) {
+  if (!capabilities || capabilities->HasKey(local_discovery::kPrivetKeyError) ||
+      !printer_lister_) {
     SendPrivetCapabilitiesError(name);
     return;
   }
 
   base::DictionaryValue printer_info;
   const local_discovery::DeviceDescription* description =
       printer_lister_->GetDeviceDescription(name);
 
   if (!description) {
     SendPrivetCapabilitiesError(name);
@@ skipping 29 matching lines @@
                  ticket,
                  capabilities,
                  page_size));
 }
 
 bool PrintPreviewHandler::CreatePrivetHTTP(
     const std::string& name,
     const local_discovery::PrivetHTTPAsynchronousFactory::ResultCallback&
         callback) {
   const local_discovery::DeviceDescription* device_description =
-      printer_lister_->GetDeviceDescription(name);
+      printer_lister_ ? printer_lister_->GetDeviceDescription(name) : NULL;
 
   if (!device_description) {
     SendPrivetCapabilitiesError(name);
     return false;
   }
 
   privet_http_factory_ =
       local_discovery::PrivetHTTPAsynchronousFactory::CreateInstance(
           service_discovery_client_,
           Profile::FromWebUI(web_ui())->GetRequestContext());
@@ skipping 47 matching lines @@
 
 void PrintPreviewHandler::UnregisterForMergeSession() {
   if (reconcilor_)
     reconcilor_->RemoveMergeSessionObserver(this);
 }
 
 void PrintPreviewHandler::SetPdfSavedClosureForTesting(
     const base::Closure& closure) {
   pdf_file_saved_closure_ = closure;
 }