Remove unnecessary 'virtual' annotation from mojo

mojo/services/html_viewer/blink_url_request_type_converters.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/services/html_viewer/blink_url_request_type_converters.h"
 
 #include "base/strings/string_util.h"
 #include "third_party/WebKit/public/platform/WebHTTPHeaderVisitor.h"
 #include "third_party/WebKit/public/platform/WebURLRequest.h"
 #include "third_party/mojo/src/mojo/public/cpp/system/data_pipe.h"
 
 namespace mojo {
 namespace {
 
 // Ripped from web_url_loader_impl.cc.
 class HeaderFlattener : public blink::WebHTTPHeaderVisitor {
  public:
   HeaderFlattener() : has_accept_header_(false) {}
 
-  virtual void visitHeader(const blink::WebString& name,
-                           const blink::WebString& value) {
+  void visitHeader(const blink::WebString& name,
+                   const blink::WebString& value) override {
     // Headers are latin1.
     const std::string& name_latin1 = name.latin1();
     const std::string& value_latin1 = value.latin1();
 
     // Skip over referrer headers found in the header map because we already
     // pulled it out as a separate parameter.
     if (LowerCaseEqualsASCII(name_latin1, "referer"))
       return;
 
     if (LowerCaseEqualsASCII(name_latin1, "accept"))
@@ skipping 69 matching lines @@
   request.visitHTTPHeaderFields(&flattener);
   url_request->headers = flattener.GetBuffer().Pass();
 
   AddRequestBody(url_request.get(), request);
 
   return url_request.Pass();
 }
 
 }  // namespace mojo