Stop forcing optional permission on usbDevices section

chrome/common/extensions/permissions/api_permission.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_PERMISSIONS_API_PERMISSION_H_
 #define CHROME_COMMON_EXTENSIONS_PERMISSIONS_API_PERMISSION_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 203 matching lines @@
   enum Flag {
     kFlagNone = 0,
 
     // Indicates if the permission implies full access (native code).
     kFlagImpliesFullAccess = 1 << 0,
 
     // Indicates if the permission implies full URL access.
     kFlagImpliesFullURLAccess = 1 << 1,
 
     // Indicates that extensions cannot specify the permission as optional.
-    kFlagCannotBeOptional = 1 << 3,
-
-    // Indicates that extensions must specify the permission as optional.
-    kFlagMustBeOptional = 1 << 4
+    kFlagCannotBeOptional = 1 << 3
   };
 
   typedef APIPermission* (*APIPermissionConstructor)(const APIPermissionInfo*);
 
   typedef std::set<APIPermission::ID> IDSet;
 
   ~APIPermissionInfo();
 
   // Creates a APIPermission instance.
   APIPermission* CreateAPIPermission() const;
@@ skipping 19 matching lines @@
   bool implies_full_url_access() const {
     return (flags_ & kFlagImpliesFullURLAccess) != 0;
   }
 
   // Returns true if this permission can be added and removed via the
   // optional permissions extension API.
   bool supports_optional() const {
     return (flags_ & kFlagCannotBeOptional) == 0;
   }
 
-  // Returns true if this permission must be added and removed via the
-  // optional permissions extension API.
-  bool must_be_optional() const {
-    return (flags_ & kFlagMustBeOptional) != 0;
-  }
-
  private:
   // Instances should only be constructed from within a
   // PermissionsInfo::Delegate.
   friend class ChromeAPIPermissions;
   // Implementations of APIPermission will want to get the permission message,
   // but this class's implementation should be hidden from everyone else.
   friend class APIPermission;
 
   explicit APIPermissionInfo(
       APIPermission::ID id,
@@ skipping 11 matching lines @@
   const char* const name_;
   const int flags_;
   const int l10n_message_id_;
   const PermissionMessage::ID message_id_;
   const APIPermissionConstructor api_permission_constructor_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_COMMON_EXTENSIONS_PERMISSIONS_API_PERMISSION_H_