Standardize usage of virtual/override/final in extensions/

extensions/renderer/console.cc

Index: extensions/renderer/console.cc
diff --git a/extensions/renderer/console.cc b/extensions/renderer/console.cc
index f48678c4202d736b2aa6be2312aebc16573919b4..ccfef7590e619f35de1676a3fa2ace1402f0473a 100644
--- a/extensions/renderer/console.cc
+++ b/extensions/renderer/console.cc
@@ -37,7 +37,7 @@ class ByContextFinder : public content::RenderViewVisitor {
   explicit ByContextFinder(v8::Handle<v8::Context> context)
       : context_(context), found_(NULL) {}
 
-  virtual bool Visit(content::RenderView* render_view) override {
+  bool Visit(content::RenderView* render_view) override {
     ExtensionHelper* helper = ExtensionHelper::Get(render_view);
     if (helper &&
         helper->dispatcher()->script_context_set().GetByV8Context(context_)) {