Stop returning unused return value from QuicPacketCreator::CopyToBuffer.

net/quic/quic_packet_creator.h

Index: net/quic/quic_packet_creator.h
diff --git a/net/quic/quic_packet_creator.h b/net/quic/quic_packet_creator.h
index b279d512ac54a306e806d2e21b80e5e40e87e37e..bf9035b5c547cb4101d52d18e2088c5788f6d38c 100644
--- a/net/quic/quic_packet_creator.h
+++ b/net/quic/quic_packet_creator.h
@@ -214,16 +214,15 @@ class NET_EXPORT_PRIVATE QuicPacketCreator {
 
   // Converts a raw payload to a frame which fits into the current open
   // packet.  The payload begins at |iov_offset| into the |iov|.
-  // Returns the number of bytes consumed from data.
   // If data is empty and fin is true, the expected behavior is to consume the
   // fin but return 0.  If any data is consumed, it will be copied into a
   // new buffer that |frame| will point to and own.
-  size_t CreateStreamFrame(QuicStreamId id,
-                           QuicIOVector iov,
-                           size_t iov_offset,
-                           QuicStreamOffset offset,
-                           bool fin,
-                           QuicFrame* frame);
+  void CreateStreamFrame(QuicStreamId id,
+                         QuicIOVector iov,
+                         size_t iov_offset,
+                         QuicStreamOffset offset,
+                         bool fin,
+                         QuicFrame* frame);
 
   // Copies |length| bytes from iov starting at offset |iov_offset| into buffer.
   // |iov| must be at least iov_offset+length total length and buffer must be