Implement SetDefersLoading on content::URLLoaderClientImpl

content/child/test_request_peer.h

Index: content/child/test_request_peer.h
diff --git a/content/child/test_request_peer.h b/content/child/test_request_peer.h
index 81162acde553f1d0ccd5fa1813e5fad4cbceedfa..e076b0dcbd5f3662a29d573a59be35e0db0a0adf 100644
--- a/content/child/test_request_peer.h
+++ b/content/child/test_request_peer.h
@@ -65,6 +65,8 @@ class TestRequestPeer : public RequestPeer {
     // Total encoded data length, regardless of whether downloading to a file or
     // not.
     int total_encoded_data_length = 0;
+    bool defer_on_transfer_size_updated = false;
+
     // Total length when downloading to a file.
     int total_downloaded_data_length = 0;