Standardize usage of virtual/override/final in content/

content/public/test/mock_resource_context.h

Index: content/public/test/mock_resource_context.h
diff --git a/content/public/test/mock_resource_context.h b/content/public/test/mock_resource_context.h
index b8e2c8cf1727d475f57969333669dac963e59e7e..91ec2d33b988136d49f3ee574ba62a36c8b9b514 100644
--- a/content/public/test/mock_resource_context.h
+++ b/content/public/test/mock_resource_context.h
@@ -23,11 +23,11 @@ class MockResourceContext : public ResourceContext {
   // Does not take ownership of |test_request_context|.
   explicit MockResourceContext(net::URLRequestContext* test_request_context);
 
-  virtual ~MockResourceContext();
+  ~MockResourceContext() override;
 
   // ResourceContext implementation:
-  virtual net::HostResolver* GetHostResolver() override;
-  virtual net::URLRequestContext* GetRequestContext() override;
+  net::HostResolver* GetHostResolver() override;
+  net::URLRequestContext* GetRequestContext() override;
 
  private:
   net::URLRequestContext* test_request_context_;