net: Explicitly close a file stream in UploadDataStream.

net/base/upload_data_stream.cc

Index: net/base/upload_data_stream.cc
diff --git a/net/base/upload_data_stream.cc b/net/base/upload_data_stream.cc
index 2d2a3a56fab3c48080cb6bb0de2cd2d57bbb76bb..8c94e08c2ee68c9ad297a1e6be41801d6a2cd68b 100644
--- a/net/base/upload_data_stream.cc
+++ b/net/base/upload_data_stream.cc
@@ -165,7 +165,12 @@ void UploadDataStream::AdvanceToNextElement() {
   ++element_index_;
   element_offset_ = 0;
   element_file_bytes_remaining_ = 0;
-  element_file_stream_.reset();
+  if (element_file_stream_.get()) {
+    // Temporarily allow until fix: http://crbug.com/72001.
+    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    element_file_stream_->Close();
+    element_file_stream_.reset();
+  }
 }
 
 bool UploadDataStream::IsEOF() const {