[DevTools] Introduce ServiceWorkerVersion.ScriptLastModified/ScriptResponseTime

Source/devtools/protocol.json

Index: Source/devtools/protocol.json
diff --git a/Source/devtools/protocol.json b/Source/devtools/protocol.json
index bc9dbe38c7bb8decb36979970198975a85609fa2..92bb2d92a9e9099cb327e4d55c9e51894ad32ced 100644
--- a/Source/devtools/protocol.json
+++ b/Source/devtools/protocol.json
@@ -4075,7 +4075,8 @@
                     { "name": "scriptURL", "type": "string" },
                     { "name": "runningStatus", "$ref": "ServiceWorkerVersionRunningStatus" },
                     { "name": "status", "$ref": "ServiceWorkerVersionStatus" },
-                    { "name": "updateTime", "type": "number", "optional": true}
+                    { "name": "scriptLastModified", "type": "number", "optional": true, "description": "The Last-Modified header value of the main script." },
+                    { "name": "scriptResponseTime", "type": "number", "optional": true, "description": "The time at which the response headers of the main script were received from the server.  For cached script it is the last time the cache entry was validated." }
                 ]
             },
             {