media: Send chrome-cache: frfr on first request.

media/blink/multibuffer_data_source.cc

Index: media/blink/multibuffer_data_source.cc
diff --git a/media/blink/multibuffer_data_source.cc b/media/blink/multibuffer_data_source.cc
index c882fae9e32c6075f55ec8188086a1398b34377f..4d8d045ab05e4ea40eb368ff577c37ab6daeba0a 100644
--- a/media/blink/multibuffer_data_source.cc
+++ b/media/blink/multibuffer_data_source.cc
@@ -403,7 +403,7 @@ void MultibufferDataSource::ReadTask() {
     bytes_read =
         static_cast<int>(std::min<int64_t>(available, read_op_->size()));
     bytes_read = reader_->TryRead(read_op_->data(), bytes_read);
-
+    url_data_->AddBytesRead(bytes_read);
     if (bytes_read == 0 && total_bytes_ == kPositionNotSpecified) {
       // We've reached the end of the file and we didn't know the total size
       // before. Update the total size so Read()s past the end of the file will