Enable _api_features.json to block APIs from service worker contexts.

chrome/common/extensions/features/api_feature.h

 // 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.
 
 #ifndef CHROME_COMMON_EXTENSIONS_FEATURES_API_FEATURE_H_
 #define CHROME_COMMON_EXTENSIONS_FEATURES_API_FEATURE_H_
 
 #include "chrome/common/extensions/features/simple_feature.h"
 
 namespace extensions {
 
 class APIFeature : public SimpleFeature {
  public:
   APIFeature();
   virtual ~APIFeature();
 
+  // extensions::Feature:
   virtual bool IsInternal() const OVERRIDE;
+  virtual bool IsBlockedInServiceWorker() const OVERRIDE;
 
   virtual std::string Parse(const base::DictionaryValue* value) OVERRIDE;
 
  private:
   bool internal_;
+  bool blocked_in_service_worker_;
 };
 
-}  // extensions
+}  // namespace extensions
 
 #endif  // CHROME_COMMON_EXTENSIONS_FEATURES_API_FEATURE_H_