Update documentation for HTTP response status code

runtime/bin/http.dart

Index: runtime/bin/http.dart
diff --git a/runtime/bin/http.dart b/runtime/bin/http.dart
index 29a76acb36f99e66bb1479a36905ef1dde6cce97..0b9cd30028730ca93c578764076fe4ac3b8505d4 100644
--- a/runtime/bin/http.dart
+++ b/runtime/bin/http.dart
@@ -589,9 +589,10 @@ abstract class HttpResponse {
   int contentLength;
 
   /**
-   * Gets and sets the status code. Any integer value is accepted, but
-   * for the official HTTP status codes use the fields from
-   * [HttpStatus].
+   * Gets and sets the status code. Any integer value is accepted. For
+   * the official HTTP status codes use the fields from
+   * [HttpStatus]. If no status code is explicitly set the default
+   * value [HttpStatus.OK] is used.
    */
   int statusCode;