[dotnet] Use source-generated JSON for event args

Author: RenderMichael

third_party/dotnet/devtools/src/generator/CodeGen/DomainGenerator.cs

@@ -2,6 +2,7 @@
 using Microsoft.Extensions.DependencyInjection;
 using OpenQA.Selenium.DevToolsGenerator.ProtocolDefinition;
 using System;
+using System.Linq;
 using System.Collections.Generic;
 
 namespace OpenQA.Selenium.DevToolsGenerator.CodeGen
@@ -61,7 +62,8 @@ public override IDictionary<string, string> GenerateCode(DomainDefinition domain
                 domain = domainDefinition,
                 className = className,
                 rootNamespace = Settings.RootNamespace,
-                context = context
+                context = context,
+                protocolVersion = Settings.RootNamespace.Split('.').Last()
             });
 
             var outputPath = Utility.ReplaceTokensInPath(Settings.DefinitionTemplates.DomainTemplate.OutputPath, className, context, Settings);

third_party/dotnet/devtools/src/generator/Templates/domain.hbs

@@ -60,7 +60,7 @@ namespace {{rootNamespace}}.{{domain.Name}}
                 if (m_eventMap.ContainsKey(e.EventName))
                 {
                     var eventData = m_eventMap[e.EventName];
-                    var eventArgs = e.EventData.Deserialize(eventData.EventArgsType, global::OpenQA.Selenium.DevTools.Json.DevToolsJsonOptions.Default);
+                    var eventArgs = e.EventData.Deserialize(eventData.EventArgsType, {{rootNamespace}}.{{protocolVersion}}JsonSerializerContext.Default.Options);
                     eventData.EventInvoker(eventArgs);
                 }
             }