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

chrome/browser/ui/webui/print_preview/print_preview_handler.cc

 // Copyright (c) 2012 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 "chrome/browser/ui/webui/print_preview/print_preview_handler.h"
 
 #include <ctype.h>
 
 #include <string>
 
@@ skipping 284 matching lines @@
       OAuth2TokenService::ScopeSet oauth_scopes;
       oauth_scopes.insert(kCloudPrintAuth);
       scoped_ptr<OAuth2TokenService::Request> request(
           service->StartRequest(oauth_scopes, this));
       requests_[type].reset(request.release());
     } else {
       handler_->SendAccessToken(type, std::string());  // Unknown type.
     }
   }
 
-  void OnGetTokenSuccess(const OAuth2TokenService::Request* request,
-                         const std::string& access_token,
-                         const base::Time& expiration_time) OVERRIDE {
+  virtual void OnGetTokenSuccess(const OAuth2TokenService::Request* request,
+                                 const std::string& access_token,
+                                 const base::Time& expiration_time) OVERRIDE {
     OnServiceResponce(request, access_token);
   }
 
-  void OnGetTokenFailure(const OAuth2TokenService::Request* request,
-                         const GoogleServiceAuthError& error) OVERRIDE {
+  virtual void OnGetTokenFailure(const OAuth2TokenService::Request* request,
+                                 const GoogleServiceAuthError& error) OVERRIDE {
     OnServiceResponce(request, std::string());
   }
 
  private:
   void OnServiceResponce(const OAuth2TokenService::Request* request,
                          const std::string& access_token) {
     for (Requests::iterator i = requests_.begin(); i != requests_.end(); ++i) {
       if (i->second == request) {
         handler_->SendAccessToken(i->first, access_token);
         requests_.erase(i);
@@ skipping 761 matching lines @@
     // Nothing to print, no preview available.
     return false;
   }
   DCHECK(tmp_data->size() && tmp_data->front());
 
   *data = tmp_data;
   *title = print_preview_ui->initiator_tab_title();
   return true;
 }