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

chrome/common/extensions/features/base_feature_provider.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/common/extensions/features/base_feature_provider.h"
 
 #include "base/json/json_reader.h"
 #include "base/lazy_instance.h"
 #include "chrome/common/extensions/features/api_feature.h"
 #include "chrome/common/extensions/features/complex_feature.h"
@@ skipping 14 matching lines @@
 class LazyFeatureProvider : public FeatureProvider {
  public:
   LazyFeatureProvider(const std::string& name,
                       BaseFeatureProvider::FeatureFactory factory,
                       int resource_id)
       : name_(name),
         factory_(factory),
         resource_id_(resource_id) {
   }
 
-  virtual Feature* GetFeature(const std::string& name) {
+  virtual Feature* GetFeature(const std::string& name) OVERRIDE {
     return GetBaseFeatureProvider()->GetFeature(name);
   }
 
-  virtual std::set<std::string> GetAllFeatureNames() {
+  virtual std::set<std::string> GetAllFeatureNames() OVERRIDE {
     return GetBaseFeatureProvider()->GetAllFeatureNames();
   }
 
  private:
   BaseFeatureProvider* GetBaseFeatureProvider() {
     if (!features_)
       features_ = LoadProvider();
     return features_.get();
   }
 
@@ skipping 137 matching lines @@
 
 Feature* BaseFeatureProvider::GetFeature(const std::string& name) {
   FeatureMap::iterator iter = features_.find(name);
   if (iter != features_.end())
     return iter->second.get();
   else
     return NULL;
 }
 
 }  // namespace