Standardize usage of virtual/override/final in content/

content/child/child_message_filter.h

Index: content/child/child_message_filter.h
diff --git a/content/child/child_message_filter.h b/content/child/child_message_filter.h
index a7bc7b92e47f48ec15d5dbb15ccb6a6eeaa77b62..a79ceecf2dec43460d87d8f67dd9913437abc276 100644
--- a/content/child/child_message_filter.h
+++ b/content/child/child_message_filter.h
@@ -27,7 +27,7 @@ class ChildMessageFilter
       public IPC::Sender {
  public:
   // IPC::Sender implementation. Can be called on any threads.
-  virtual bool Send(IPC::Message* message) override;
+  bool Send(IPC::Message* message) override;
 
   // If implementers want to run OnMessageReceived on a different task
   // runner it should override this and return the TaskRunner for the message.
@@ -47,7 +47,7 @@ class ChildMessageFilter
 
  protected:
   ChildMessageFilter();
-  virtual ~ChildMessageFilter();
+  ~ChildMessageFilter() override;
 
  private:
   class Internal;