Fix crash from ipc_fuzzer

chrome/browser/printing/print_view_manager_base.cc

 // Copyright 2013 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_view_manager_base.h"
 
+#include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/timer/timer.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/printing/print_job.h"
 #include "chrome/browser/printing/print_job_manager.h"
 #include "chrome/browser/printing/printer_query.h"
@@ skipping 16 matching lines @@
 #include "chrome/browser/printing/print_error_dialog.h"
 #endif
 
 using base::TimeDelta;
 using content::BrowserThread;
 
 namespace printing {
 
 namespace {
 
+void ShowWarningMessageBox(const base::string16& message) {
+  // Runs always on the UI thread.
+  static bool is_dialog_shown = false;
+  if (is_dialog_shown)
+    return;
+  // Block opening dialog from nested task.
+  base::AutoReset<bool> auto_reset(&is_dialog_shown, true);
+
+  chrome::ShowMessageBox(nullptr, base::string16(), message,
+                         chrome::MESSAGE_BOX_TYPE_WARNING);
+}
+
 }  // namespace
 
 PrintViewManagerBase::PrintViewManagerBase(content::WebContents* web_contents)
     : content::WebContentsObserver(web_contents),
       number_pages_(0),
       printing_succeeded_(false),
       inside_inner_message_loop_(false),
       cookie_(0),
       queue_(g_browser_process->print_job_manager()->queue()) {
   DCHECK(queue_.get());
@@ skipping 135 matching lines @@
 
   ReleasePrinterQuery();
 
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_PRINT_JOB_RELEASED,
       content::Source<content::WebContents>(web_contents()),
       content::NotificationService::NoDetails());
 }
 
 void PrintViewManagerBase::OnShowInvalidPrinterSettingsError() {
-  chrome::ShowMessageBox(NULL,
-                         base::string16(),
-                         l10n_util::GetStringUTF16(
-                             IDS_PRINT_INVALID_PRINTER_SETTINGS),
-                         chrome::MESSAGE_BOX_TYPE_WARNING);
+  base::MessageLoop::current()->PostTask(
+      FROM_HERE, base::Bind(&ShowWarningMessageBox,
+                            l10n_util::GetStringUTF16(
+                                IDS_PRINT_INVALID_PRINTER_SETTINGS)));
 }
 
 void PrintViewManagerBase::DidStartLoading() {
   UpdateScriptedPrintingBlocked();
 }
 
 bool PrintViewManagerBase::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(PrintViewManagerBase, message)
     IPC_MESSAGE_HANDLER(PrintHostMsg_DidGetPrintedPagesCount,
@@ skipping 301 matching lines @@
   scoped_refptr<printing::PrinterQuery> printer_query;
   printer_query = queue_->PopPrinterQuery(cookie);
   if (!printer_query.get())
     return;
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
       base::Bind(&PrinterQuery::StopWorker, printer_query.get()));
 }
 
 }  // namespace printing