Standardize usage of virtual/override/final in printing/

printing/printing_context_mac.h

Index: printing/printing_context_mac.h
diff --git a/printing/printing_context_mac.h b/printing/printing_context_mac.h
index 37015979ee005acb5a8f2490225d988fb5f151ea..561b25d4794032aa71b2612b4f57c6cbab1106e9 100644
--- a/printing/printing_context_mac.h
+++ b/printing/printing_context_mac.h
@@ -22,25 +22,24 @@ namespace printing {
 class PRINTING_EXPORT PrintingContextMac : public PrintingContext {
  public:
   explicit PrintingContextMac(Delegate* delegate);
-  virtual ~PrintingContextMac();
+  ~PrintingContextMac() override;
 
   // PrintingContext implementation.
-  virtual void AskUserForSettings(
-      int max_pages,
-      bool has_selection,
-      const PrintSettingsCallback& callback) override;
-  virtual Result UseDefaultSettings() override;
-  virtual gfx::Size GetPdfPaperSizeDeviceUnits() override;
-  virtual Result UpdatePrinterSettings(bool external_preview,
-                                       bool show_system_dialog) override;
-  virtual Result InitWithSettings(const PrintSettings& settings) override;
-  virtual Result NewDocument(const base::string16& document_name) override;
-  virtual Result NewPage() override;
-  virtual Result PageDone() override;
-  virtual Result DocumentDone() override;
-  virtual void Cancel() override;
-  virtual void ReleaseContext() override;
-  virtual gfx::NativeDrawingContext context() const override;
+  void AskUserForSettings(int max_pages,
+                          bool has_selection,
+                          const PrintSettingsCallback& callback) override;
+  Result UseDefaultSettings() override;
+  gfx::Size GetPdfPaperSizeDeviceUnits() override;
+  Result UpdatePrinterSettings(bool external_preview,
+                               bool show_system_dialog) override;
+  Result InitWithSettings(const PrintSettings& settings) override;
+  Result NewDocument(const base::string16& document_name) override;
+  Result NewPage() override;
+  Result PageDone() override;
+  Result DocumentDone() override;
+  void Cancel() override;
+  void ReleaseContext() override;
+  gfx::NativeDrawingContext context() const override;
 
  private:
   // Initializes PrintSettings from |print_info_|. This must be called