[chromedriver] Fix a confusing error message.

chrome/test/chromedriver/chrome/devtools_http_client.cc

Index: chrome/test/chromedriver/chrome/devtools_http_client.cc
diff --git a/chrome/test/chromedriver/chrome/devtools_http_client.cc b/chrome/test/chromedriver/chrome/devtools_http_client.cc
index 8bdff444db0f128a6ef15e348557c7554a267ddd..f2b2d1c5c5a4a19816559cf0973e7d503e9af9b9 100644
--- a/chrome/test/chromedriver/chrome/devtools_http_client.cc
+++ b/chrome/test/chromedriver/chrome/devtools_http_client.cc
@@ -260,10 +260,8 @@ Status DevToolsHttpClient::CloseFrontends(const std::string& for_client_id) {
       return status;
 
     const WebViewInfo* view_info = views_info.GetForId(for_client_id);
-    if (!view_info) {
-      return Status(kDisconnected,
-                    "DevTools client closed during closing UI debuggers");
-    }
+    if (!view_info)
+      return Status(kNoSuchWindow, "window was already closed");
     if (view_info->debugger_url.size())
       return Status(kOk);