Update {virtual,override} to follow C++11 style in printing.

The Google style guide states that only one of {virtual,override,final} should be used for each declaration, since override implies virtual and final implies both virtual and override.

This patch was manually generated using a regex and a text editor.

BUG=417463

Review URL: https://codereview.chromium.org/1101023002

Cr-Commit-Position: refs/heads/master@{#327173}
diff --git a/printing/printing_context_system_dialog_win.h b/printing/printing_context_system_dialog_win.h
index 5e11aa5d..bafc478c 100644
--- a/printing/printing_context_system_dialog_win.h
+++ b/printing/printing_context_system_dialog_win.h
@@ -19,10 +19,10 @@
     : public PrintingContextWin {
  public:
   explicit PrintingContextSytemDialogWin(Delegate* delegate);
-  virtual ~PrintingContextSytemDialogWin();
+  ~PrintingContextSytemDialogWin() override;
 
   // PrintingContext implementation.
-  virtual void AskUserForSettings(
+  void AskUserForSettings(
       int max_pages,
       bool has_selection,
       bool is_scripted,