Inspector: wrapped inspector agent instances into factory-like wrappers

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 30 matching lines @@
 
     $domainClassName* $domainFieldName() { return &m_$domainFieldName; }
 
 """)
 
 backend_method = (
 """void InspectorBackendDispatcherImpl::${domainName}_$methodName(long callId, InspectorObject*$requestMessageObject)
 {
     RefPtr<InspectorArray> protocolErrors = InspectorArray::create();
 
-    if (!$agentField)
+    $handlerClass* handler = $agentField ? $agentField->getCommandHandler() : 0;
+    if (!handler)
         protocolErrors->pushString("${domainName} handler is not available.");
 $methodOutCode
 $methodInCode
     RefPtr<InspectorObject> result = InspectorObject::create();
     ErrorString error;
     if (!protocolErrors->length()) {
-        $agentField->$methodName(&error$agentCallParams);
+        handler->$methodName(&error$agentCallParams);
 
 ${responseCook}
     }
     sendResponse(callId, result, commandNames[$commandNameIndex], protocolErrors, error);
 }
 """)
 
 frontend_method = ("""void InspectorFrontend::$domainName::$eventName($parameters)
 {
     RefPtr<InspectorObject> jsonMessage = InspectorObject::create();
@@ skipping 851 matching lines @@
     };
 
 """)
 
 class_binding_builder_part_4 = (
 """    static Builder<NoFieldsSet> create()
     {
         return Builder<NoFieldsSet>(InspectorObject::create());
     }
 """)