DevTools: respond with error when Debugger command is sent to disabled debugger agent

Source/core/inspector/CodeGeneratorInspectorStrings.py

 # Copyright (c) 2013 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 35 matching lines @@
 """void InspectorBackendDispatcherImpl::${domainName}_$methodName(int callId, JSONObject*$requestMessageObject, JSONArray* protocolErrors)
 {
     if (!$agentField)
         protocolErrors->pushString("${domainName} handler is not available.");
 $methodCode
     if (protocolErrors->length()) {
         reportProtocolError(callId, InvalidParams, String::format(InvalidParamsFormatString, commandName($commandNameIndex)), protocolErrors);
         return;
     }
 $agentCallParamsDeclaration
+$agentEnablementCheck
     $agentField->$methodName($agentCallParams);
 $responseCook
     sendResponse(callId, $sendResponseCallParams);
 }
 """)
 
 frontend_method = ("""void InspectorFrontend::$domainName::$eventName($parameters)
 {
     RefPtr<JSONObject> jsonMessage = JSONObject::create();
     jsonMessage->setString("method", "$domainName.$eventName");
@@ skipping 839 matching lines @@
     };
 
 """)
 
 class_binding_builder_part_4 = (
 """    static Builder<NoFieldsSet> create()
     {
         return Builder<NoFieldsSet>(JSONObject::create());
     }
 """)