Warn on missing OVERRIDE/virtual everywhere, not just in header files.

chrome/test/chromedriver/chrome/devtools_event_logger_unittest.cc

 // Copyright (c) 2013 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 "base/format_macros.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/json/string_escape.h"
 #include "base/stringprintf.h"
 #include "base/time.h"
@@ skipping 33 matching lines @@
       const base::DictionaryValue& params,
       scoped_ptr<base::DictionaryValue>* result) OVERRIDE {
     sent_command_queue_.push_back(method);
     return Status(kOk);
   }
 
   virtual void AddListener(DevToolsEventListener* listener) OVERRIDE {
     listener_ = listener;
   }
 
-  const std::string& GetId() OVERRIDE {
+  virtual const std::string& GetId() OVERRIDE {
     return id_;
   }
 
  private:
   const std::string id_;
   std::list<std::string> sent_command_queue_;
   DevToolsEventListener* listener_;
 };
 
 scoped_ptr<DictionaryValue> ParseDictionary(const std::string& json) {
@@ skipping 99 matching lines @@
 
   client1.TriggerEvent("Console.gaga1");
   client2.TriggerEvent("Console.gaga2");
 
   scoped_ptr<base::ListValue> entries(logger.GetAndClearLogEntries());
 
   ASSERT_EQ(2u, entries->GetSize());
   ValidateLogEntry(entries.get(), 0, "webview-1", "Console.gaga1", "INFO");
   ValidateLogEntry(entries.get(), 1, "webview-2", "Console.gaga2", "INFO");
 }