cashew: support "usage requests allowed OTA only" policy

src/policy.h

 // Copyright (c) 2010 The Chromium OS 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 SRC_POLICY_H_
 #define SRC_POLICY_H_
 
 #include <glib.h>
 
 #include <string>
@@ skipping 13 matching lines @@
     // how often should a service request updates via the carrier usage API?
     // return value is in seconds
     virtual guint GetUpdateTimerIdleSecs(const DataPlanList& plans) const = 0;
 
     // should we emit a data plans update for the change from |old_plans|
     // to |new_plans|?
     // NOTE: user might also want to influence this from the Chrome side
     virtual bool ShouldEmitDataPlansUpdate(const DataPlanList& old_plans,
         const DataPlanList& new_plans) const = 0;
 
+    // must usage API requests for a cellular service be sent over the air?
+    virtual bool UsageRequestsMustBeSentOTA() const = 0;
+
     // factory
     // return appropriate concrete impl for |carrier|
     // caller owns returned Policy and is responsible for deleting it
     static Policy* GetPolicy(const std::string& carrier);
 };
 
 }  // namespace cashew
 
 #endif  // SRC_POLICY_H_