Fix two URLRequestJob subclasses that didn't support cancellation

net/url_request/url_request_error_job.h

Index: net/url_request/url_request_error_job.h
diff --git a/net/url_request/url_request_error_job.h b/net/url_request/url_request_error_job.h
index 059db266f3c599e0291f6b68193ddc3801729b17..efd6b6696e8e4fc1c83e8630cd1235495d0b5c4b 100644
--- a/net/url_request/url_request_error_job.h
+++ b/net/url_request/url_request_error_job.h
@@ -21,6 +21,7 @@ class NET_EXPORT URLRequestErrorJob : public URLRequestJob {
                      int error);
 
   void Start() override;
+  void Kill() override;
 
  private:
   ~URLRequestErrorJob() override;