cashew: support "usage requests allowed OTA only" policy

src/default_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_DEFAULT_POLICY_H_
 #define SRC_DEFAULT_POLICY_H_
 
 #include <string>
 
 #include <base/basictypes.h>  // NOLINT
 
 #include "src/policy.h"
 
 namespace cashew {
 
 // a bare-bones default carrier policy
 class DefaultPolicy: public Policy {
   public:
 
     explicit DefaultPolicy(const std::string& carrier);
     virtual ~DefaultPolicy();
 
     virtual const std::string& GetCarrier() const;
 
     virtual guint GetUpdateTimerIdleSecs(const DataPlanList& plans) const;
 
     virtual bool ShouldEmitDataPlansUpdate(const DataPlanList& old_plans,
         const DataPlanList& new_plans) const;
 
+    virtual bool UsageRequestsMustBeSentOTA() const;
+
   private:
     // carrier
     const std::string carrier_;
 
     DISALLOW_COPY_AND_ASSIGN(DefaultPolicy);
 };
 
 }  // namespace cashew
 
 #endif  // SRC_DEFAULT_POLICY_H_