Inspector: wrapped inspector agent instances into factory-like wrappers

Source/core/inspector/CodeGeneratorInspectorStrings.py

Index: Source/core/inspector/CodeGeneratorInspectorStrings.py
diff --git a/Source/core/inspector/CodeGeneratorInspectorStrings.py b/Source/core/inspector/CodeGeneratorInspectorStrings.py
index 8131ff25eb179e6caab8a3ca7237ba63ae90ed56..961b0b173e2f9e93910b1f193a37a102524b97e4 100644
--- a/Source/core/inspector/CodeGeneratorInspectorStrings.py
+++ b/Source/core/inspector/CodeGeneratorInspectorStrings.py
@@ -48,7 +48,8 @@ backend_method = (
 {
     RefPtr<InspectorArray> protocolErrors = InspectorArray::create();
 
-    if (!$agentField)
+    $handlerClass* handler = $agentField ? $agentField->commandHandler() : 0;
+    if (!handler)
         protocolErrors->pushString("${domainName} handler is not available.");
 $methodOutCode
 $methodInCode
@@ -56,7 +57,7 @@ $methodInCode
     RefPtr<InspectorValue> resultErrorData;
     ErrorString error;
     if (!protocolErrors->length()) {
-        $agentField->$methodName(&error$agentCallParams);
+        handler->$methodName(&error$agentCallParams);
 
 $errorCook${responseCook}
     }