Standardize usage of virtual/override/final in content/

content/shell/browser/shell_browser_main_parts.h

Index: content/shell/browser/shell_browser_main_parts.h
diff --git a/content/shell/browser/shell_browser_main_parts.h b/content/shell/browser/shell_browser_main_parts.h
index 09b78f277b95574aa2159cc7610bc6d44e617f14..61122a14067e4cdca9381933b231dfba5038b2d0 100644
--- a/content/shell/browser/shell_browser_main_parts.h
+++ b/content/shell/browser/shell_browser_main_parts.h
@@ -32,15 +32,15 @@ class ShellDevToolsDelegate;
 class ShellBrowserMainParts : public BrowserMainParts {
  public:
   explicit ShellBrowserMainParts(const MainFunctionParams& parameters);
-  virtual ~ShellBrowserMainParts();
+  ~ShellBrowserMainParts() override;
 
   // BrowserMainParts overrides.
-  virtual void PreEarlyInitialization() override;
-  virtual void PreMainMessageLoopStart() override;
-  virtual void PostMainMessageLoopStart() override;
-  virtual void PreMainMessageLoopRun() override;
-  virtual bool MainMessageLoopRun(int* result_code) override;
-  virtual void PostMainMessageLoopRun() override;
+  void PreEarlyInitialization() override;
+  void PreMainMessageLoopStart() override;
+  void PostMainMessageLoopStart() override;
+  void PreMainMessageLoopRun() override;
+  bool MainMessageLoopRun(int* result_code) override;
+  void PostMainMessageLoopRun() override;
 
   ShellDevToolsDelegate* devtools_delegate() {
     return devtools_delegate_.get();