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

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 106ffcf2ab99bc0b54655fe345a2f6d82f3787a4..4ed8f73472bc10d68a192e03df35ac5df2993cf6 100644
--- a/Source/core/inspector/CodeGeneratorInspectorStrings.py
+++ b/Source/core/inspector/CodeGeneratorInspectorStrings.py
@@ -53,6 +53,7 @@ $methodCode
         return;
     }
 $agentCallParamsDeclaration
+$agentEnablementCheck
     $agentField->$methodName($agentCallParams);
 $responseCook
     sendResponse(callId, $sendResponseCallParams);