[Extensions] DCHECK that ExtensionFunctions respond (and only once)

chrome/browser/chromeos/extensions/echo_private_api.cc

 // 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.
 
 #include "chrome/browser/chromeos/extensions/echo_private_api.h"
 
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 60 matching lines @@
   std::string result;
   if (type == kCouponType) {
     provider->GetMachineStatistic(chromeos::system::kOffersCouponCodeKey,
                                   &result);
   } else if (type == kGroupType) {
     provider->GetMachineStatistic(chromeos::system::kOffersGroupCodeKey,
                                   &result);
   }
 
   results_ = echo_api::GetRegistrationCode::Results::Create(result);
-  SendResponse(true);
 }
 
 bool EchoPrivateGetRegistrationCodeFunction::RunSync() {
   std::unique_ptr<echo_api::GetRegistrationCode::Params> params =
       echo_api::GetRegistrationCode::Params::Create(*args_);
   EXTENSION_FUNCTION_VALIDATE(params);
   GetRegistrationCode(params->type);
   return true;
 }
 
@@ skipping 180 matching lines @@
 void EchoPrivateGetUserConsentFunction::Finalize(bool consent) {
   // Consent should not be true if offers redeeming is disabled.
   CHECK(redeem_offers_allowed_ || !consent);
   results_ = echo_api::GetUserConsent::Results::Create(consent);
   SendResponse(true);
 
   // Release the reference added in |OnRedeemOffersAllowedChecked|, before
   // showing the dialog.
   Release();
 }