Enforce the 'requirements' field in manifests.

chrome/browser/extensions/extension_scoped_prefs.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_BROWSER_EXTENSIONS_EXTENSION_SCOPED_PREFS_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_SCOPED_PREFS_H_
 
 class ExtensionScopedPrefs {
  public:
   ExtensionScopedPrefs() {}
   ~ExtensionScopedPrefs() {}
 
   // Sets the pref |key| for extension |id| to |value|.
   virtual void UpdateExtensionPref(const std::string& id,
                                    const std::string& key,
                                    base::Value* value) = 0;
 
+  // Sets the pref |key| for extension |id| to |value|.
+  virtual void UpdateExtensionPrefList(
+      const std::string& id,
+      const std::string& key,
+      const std::vector<std::string>& value) = 0;
+
   // Deletes the pref dictionary for extension |id|.
   virtual void DeleteExtensionPrefs(const std::string& id) = 0;
 
   // Reads a boolean pref |pref_key| from extension with id |extension_id|.
   virtual bool ReadExtensionPrefBoolean(const std::string& extension_id,
                                         const std::string& pref_key) const = 0;
 
   // Reads an integer pref |pref_key| from extension with id |extension_id|.
   virtual bool ReadExtensionPrefInteger(const std::string& extension_id,
                                         const std::string& pref_key,
                                         int* out_value) const = 0;
 
   // Reads a list pref |pref_key| from extension with id |extension_id|.
   virtual bool ReadExtensionPrefList(
       const std::string& extension_id,
       const std::string& pref_key,
       const base::ListValue** out_value) const = 0;
 
+  // Reads a list of string prefs |pref_key| from extension with id
+  // |extension_id|.
+  virtual bool ReadExtensionPrefStringList(
+      const std::string& extension_id,
+      const std::string& pref_key,
+      std::vector<std::string>* out_value) const = 0;
+
   // Reads a string pref |pref_key| from extension with id |extension_id|.
   virtual bool ReadExtensionPrefString(const std::string& extension_id,
                                        const std::string& pref_key,
                                        std::string* out_value) const = 0;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SCOPED_PREFS_H_