Add 'deadline' to HttpResponse, making it possible to give a max duration for the liveness of the r…

sdk/lib/io/http.dart

Index: sdk/lib/io/http.dart
diff --git a/sdk/lib/io/http.dart b/sdk/lib/io/http.dart
index 5d316eb7890c5356330b7c30a41fb894f6e9cf5e..6764ab2602e7903ffd74715e7fd910b4f441ca76 100644
--- a/sdk/lib/io/http.dart
+++ b/sdk/lib/io/http.dart
@@ -820,6 +820,18 @@ abstract class HttpResponse implements IOSink {
   bool persistentConnection;
 
   /**
+   * Set and get the [deadline] for the response. The deadline is timed from the
+   * time it's set. Setting a new deadline will override any previous deadline.
+   * When a deadline is exceeded, the response will be closed and any further
+   * data ignored.
+   *
+   * To disable a deadline, set the [deadline] to `null`.
+   *
+   * The [deadline] is `null` by default.
+   */
+  Duration deadline;
+
+  /**
    * Returns the response headers.
    */
   HttpHeaders get headers;