net: Fix a regression that broke file uploading with http authentication

net/base/upload_data.h

Index: net/base/upload_data.h
diff --git a/net/base/upload_data.h b/net/base/upload_data.h
index c9796ac807b1a0fbfc872f8ab3e2078a72cfc4c5..83934772566baf5fa5d21d004d0340c2fcef429d 100644
--- a/net/base/upload_data.h
+++ b/net/base/upload_data.h
@@ -129,8 +129,9 @@ class NET_EXPORT UploadData
     // Returns the number of bytes remaining to read.
     uint64 BytesRemaining();
 
-    // Resets the offset to zero, so that the element can be reread.
-    void ResetOffset() { offset_ = 0; }
+    // Resets the offset to zero and closes the file stream if opened, so
+    // that the element can be reread.
+    void ResetOffset();
 
    private:
     // Returns a FileStream opened for reading for this element, positioned