Use BaseShellDialog for print dialog on Windows

printing/printing_context_win.h

Index: printing/printing_context_win.h
diff --git a/printing/printing_context_win.h b/printing/printing_context_win.h
index c54b531b720424f05b9a7f91d1c7deeaf4756701..06226b2704fb9c7f59f7eb347eea4d2d8f6b3fc1 100644
--- a/printing/printing_context_win.h
+++ b/printing/printing_context_win.h
@@ -14,10 +14,13 @@
 #include "build/build_config.h"
 #include "printing/printing_context.h"
 #include "ui/gfx/native_widget_types.h"
+#include "ui/shell_dialogs/print_settings_dialog_win.h"
 
 namespace printing {
 
-class PRINTING_EXPORT PrintingContextWin : public PrintingContext {
+class PRINTING_EXPORT PrintingContextWin
+    : public PrintingContext,
+      public ui::PrintSettingsDialogWin::Observer {
  public:
   explicit PrintingContextWin(const std::string& app_locale);
   ~PrintingContextWin();
@@ -41,6 +44,10 @@ class PRINTING_EXPORT PrintingContextWin : public PrintingContext {
   virtual void ReleaseContext() OVERRIDE;
   virtual gfx::NativeDrawingContext context() const OVERRIDE;
 
+  // PrintSettingsDialogWin::Observer implementation:
+  virtual void PrintSettingsConfirmed(PRINTDLGEX* dialog_options) OVERRIDE;
+  virtual void PrintSettingsCancelled(PRINTDLGEX* dialog_options) OVERRIDE;
+
 #if defined(UNIT_TEST) || defined(PRINTING_IMPLEMENTATION)
   // Sets a fake PrintDlgEx function pointer in tests.
   void SetPrintDialog(HRESULT (__stdcall *print_dialog_func)(LPPRINTDLGEX)) {
@@ -88,6 +95,12 @@ class PRINTING_EXPORT PrintingContextWin : public PrintingContext {
   // SetPrintDialog() in tests.
   HRESULT (__stdcall *print_dialog_func_)(LPPRINTDLGEX);
 
+  // Where to notify when the dialog is closed.
+  PrintSettingsCallback callback_;
+
+  // Wrapper around native print dialog that runs it on a background thread.
+  scoped_refptr<ui::PrintSettingsDialogWin> print_settings_dialog_;
+
   DISALLOW_COPY_AND_ASSIGN(PrintingContextWin);
 };