cashew: support "usage requests allowed OTA only" policy

src/data_plan_provider.cc

 // 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.
 
 #include "src/data_plan_provider.h"
 
 #include <base/json/json_reader.h>
 #include <base/scoped_ptr.h>
 #include <base/values.h>
 #include <glog/logging.h>
@@ skipping 16 matching lines @@
 const std::string& DataPlanProvider::GetCarrier() const {
   return carrier_;
 }
 
 const std::string& DataPlanProvider::GetUsageUrl() const {
   return usage_url_;
 }
 
 void DataPlanProvider::SetUsageUrl(const std::string& usage_url) {
   DLOG(INFO) << carrier_ << ": SetUsageUrl: url = " << usage_url;
-  if (usage_url_.compare(usage_url)) {
+  if (usage_url_ != usage_url) {
     usage_url_ = usage_url;
     CancelPendingRequests();
   }
 }
 
 void DataPlanProvider::SetDelegate(DataPlanProviderDelegate *delegate) {
   DLOG(INFO) << carrier_ << ": SetDelegate";
   delegate_ = delegate;
   if (delegate_ == NULL) {
     CancelPendingRequests();
@@ skipping 90 matching lines @@
   if (request_in_progress_) {
     fetcher_->TerminateTransfer();
     response_buffer_.clear();
     request_in_progress_ = false;
   }
 }
 
 // private methods
 
 }  // namespace cashew