Log compressed size of HTTP/2 requests.

net/spdy/header_coalescer.h

Index: net/spdy/header_coalescer.h
diff --git a/net/spdy/header_coalescer.h b/net/spdy/header_coalescer.h
index adbdc66b8ca7e819f29918a3b076296c915d2fee..fe30a2896a98b960f8c36ff3e15c6c708aa1b51d 100644
--- a/net/spdy/header_coalescer.h
+++ b/net/spdy/header_coalescer.h
@@ -20,6 +20,8 @@ class NET_EXPORT_PRIVATE HeaderCoalescer : public SpdyHeadersHandlerInterface {
   void OnHeader(base::StringPiece key, base::StringPiece value) override;
 
   void OnHeaderBlockEnd(size_t uncompressed_header_bytes) override {}
+  void OnHeaderBlockEnd(size_t uncompressed_header_bytes,
+                        size_t compressed_header_bytes) override {}
 
   SpdyHeaderBlock release_headers();
   bool error_seen() const { return error_seen_; }