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

extensions/browser/api/bluetooth/bluetooth_private_api.h

 // Copyright 2014 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 EXTENSIONS_BROWSER_API_BLUETOOTH_BLUETOOTH_PRIVATE_API_H_
 #define EXTENSIONS_BROWSER_API_BLUETOOTH_BLUETOOTH_PRIVATE_API_H_
 
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "device/bluetooth/bluetooth_device.h"
@@ skipping 57 matching lines @@
 
   // BluetoothExtensionFunction overrides:
   bool DoWork(scoped_refptr<device::BluetoothAdapter> adapter) override;
 
   // Set of expected adapter properties to be changed.
   std::set<std::string> pending_properties_;
 
   // Set of adapter properties that were not set successfully.
   std::set<std::string> failed_properties_;
 
+  // Whether or not the function has finished parsing the arguments and queuing
+  // up state requests.
+  bool parsed_ = false;
+
   DISALLOW_COPY_AND_ASSIGN(BluetoothPrivateSetAdapterStateFunction);
 };
 
 class BluetoothPrivateSetPairingResponseFunction
     : public BluetoothExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("bluetoothPrivate.setPairingResponse",
                              BLUETOOTHPRIVATE_SETPAIRINGRESPONSE)
   BluetoothPrivateSetPairingResponseFunction();
   // BluetoothExtensionFunction overrides:
@@ skipping 93 matching lines @@
   void OnErrorCallback(device::BluetoothDevice::ConnectErrorCode error);
 
   DISALLOW_COPY_AND_ASSIGN(BluetoothPrivatePairFunction);
 };
 
 }  // namespace api
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_BLUETOOTH_BLUETOOTH_PRIVATE_API_H_