Extensions: Make it possible for permission parsing code to return a detailed error message.

chrome/common/extensions/permissions/media_galleries_permission.h

 // 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.
 
 #ifndef CHROME_COMMON_EXTENSIONS_PERMISSIONS_MEDIA_GALLERIES_PERMISSION_H_
 #define CHROME_COMMON_EXTENSIONS_PERMISSIONS_MEDIA_GALLERIES_PERMISSION_H_
 
 #include "base/basictypes.h"
 #include "chrome/common/extensions/permissions/media_galleries_permission_data.h"
 #include "chrome/common/extensions/permissions/set_disjunction_permission.h"
@@ skipping 19 matching lines @@
       : permission(permission) {}
     const std::string permission;
   };
 
   explicit MediaGalleriesPermission(const APIPermissionInfo* info);
   virtual ~MediaGalleriesPermission();
 
   // SetDisjunctionPermission overrides.
   // MediaGalleriesPermission does additional checks to make sure the
   // permissions do not contain unknown values.
-  virtual bool FromValue(const base::Value* value) OVERRIDE;
+  virtual bool FromValue(const base::Value* value, std::string* error) OVERRIDE;
 
   // APIPermission overrides.
   virtual PermissionMessages GetMessages() const OVERRIDE;
 
   // Permission strings.
   static const char kAllAutoDetectedPermission[];
   static const char kReadPermission[];
   static const char kCopyToPermission[];
   static const char kDeletePermission[];
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_COMMON_EXTENSIONS_PERMISSIONS_MEDIA_GALLERIES_PERMISSION_H_