Print preview: Delete metafiles on the right thread.

chrome/browser/ui/webui/print_preview_handler.cc

 // Copyright (c) 2011 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_handler.h"
 
 #include <ctype.h>
 
 #include <string>
 #include <vector>
@@ skipping 39 matching lines @@
 #include "printing/page_size_margins.h"
 #include "printing/print_settings.h"
 #include "unicode/ulocdata.h"
 
 #if !defined(OS_CHROMEOS)
 #include "base/command_line.h"
 #include "chrome/common/chrome_switches.h"
 #endif
 
 using content::BrowserThread;
+using printing::Metafile;
 
 namespace {
 
 enum UserActionBuckets {
   PRINT_TO_PRINTER,
   PRINT_TO_PDF,
   CANCEL,
   FALLBACK_TO_ADVANCED_SETTINGS_DIALOG,
   PREVIEW_FAILED,
   PREVIEW_STARTED,
@@ skipping 96 matching lines @@
   if (settings.GetInteger(printing::kSettingDuplexMode, &duplex_mode))
     ReportPrintSettingHistogram(duplex_mode ? DUPLEX : SIMPLEX);
 
   int color_mode;
   if (settings.GetInteger(printing::kSettingColor, &color_mode)) {
     ReportPrintSettingHistogram(
         printing::isColorModelSelected(color_mode) ? COLOR : BLACK_AND_WHITE);
   }
 }
 
+// Callback that stores a PDF file on disk.
+void PrintToPdfCallback(Metafile* metafile, const FilePath& path) {
+  metafile->SaveTo(path);
+  // |metafile| must be deleted on the UI thread.
+  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+                          base::Bind(&DeletePointer<Metafile>, metafile));
+}
+
 }  // namespace
 
-// Callback that stores a PDF file on disk.
-void PrintToPdfCallback(printing::Metafile* metafile, const FilePath& path) {
-  metafile->SaveTo(path);
-}
-
 // static
 FilePath* PrintPreviewHandler::last_saved_path_ = NULL;
 std::string* PrintPreviewHandler::last_used_printer_cloud_print_data_ = NULL;
 std::string* PrintPreviewHandler::last_used_printer_name_ = NULL;
 printing::ColorModels PrintPreviewHandler::last_used_color_model_ =
     printing::UNKNOWN_COLOR_MODEL;
 printing::MarginType PrintPreviewHandler::last_used_margins_type_ =
     printing::DEFAULT_MARGINS;
 printing::PageSizeMargins*
     PrintPreviewHandler::last_used_page_size_margins_ = NULL;
@@ skipping 614 matching lines @@
 }
 
 void PrintPreviewHandler::PostPrintToPdfTask() {
   PrintPreviewUI* print_preview_ui = static_cast<PrintPreviewUI*>(web_ui_);
   scoped_refptr<RefCountedBytes> data;
   print_preview_ui->GetPrintPreviewDataForIndex(
       printing::COMPLETE_PREVIEW_DOCUMENT_INDEX, &data);
   DCHECK(data.get());
   printing::PreviewMetafile* metafile = new printing::PreviewMetafile;
   metafile->InitFromData(static_cast<const void*>(data->front()), data->size());
+  // PrintToPdfCallback takes ownership of |metafile|.
   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
-                          base::Bind(&PrintToPdfCallback, base::Owned(metafile),
+                          base::Bind(&PrintToPdfCallback, metafile,
                                      *print_to_pdf_path_));
   print_to_pdf_path_.reset();
   ActivateInitiatorTabAndClosePreviewTab();
 }
 
 void PrintPreviewHandler::FileSelectionCanceled(void* params) {
   PrintPreviewUI* print_preview_ui = static_cast<PrintPreviewUI*>(web_ui_);
   print_preview_ui->OnFileSelectionCancelled();
 }
 
 void PrintPreviewHandler::ClearInitiatorTabDetails() {
   TabContentsWrapper* initiator_tab = GetInitiatorTab();
   if (!initiator_tab)
     return;
 
   // We no longer require the initiator tab details. Remove those details
   // associated with the preview tab to allow the initiator tab to create
   // another preview tab.
   printing::PrintPreviewTabController* tab_controller =
       printing::PrintPreviewTabController::GetInstance();
   if (tab_controller)
     tab_controller->EraseInitiatorTabInfo(preview_tab_wrapper());
 }