Standardize usage of virtual/override/final in content/

content/test/plugin/plugin_windowless_test.h

Index: content/test/plugin/plugin_windowless_test.h
diff --git a/content/test/plugin/plugin_windowless_test.h b/content/test/plugin/plugin_windowless_test.h
index 53848ff5c500f0cea5cdaabae82d9f98a13071fc..466d552d4e5d8df08ef3f64d70f57c0c3678d79e 100644
--- a/content/test/plugin/plugin_windowless_test.h
+++ b/content/test/plugin/plugin_windowless_test.h
@@ -18,12 +18,15 @@ class WindowlessPluginTest : public PluginTest {
   WindowlessPluginTest(NPP id, NPNetscapeFuncs *host_functions);
 
   // These tests run in windowless plugin mode.
-  virtual bool IsWindowless() const override;
+  bool IsWindowless() const override;
 
   // NPAPI HandleEvent handler
-  virtual NPError New(uint16 mode, int16 argc, const char* argn[],
-                      const char* argv[], NPSavedData* saved) override;
-  virtual int16 HandleEvent(void* event) override;
+  NPError New(uint16 mode,
+              int16 argc,
+              const char* argn[],
+              const char* argv[],
+              NPSavedData* saved) override;
+  int16 HandleEvent(void* event) override;
 
  protected:
   NPError ExecuteScript(NPNetscapeFuncs* browser, NPP id,