Improve memory estimate of SpdySessionPool in net/ MemoryDumpProvider.

net/spdy/spdy_stream.h

Index: net/spdy/spdy_stream.h
diff --git a/net/spdy/spdy_stream.h b/net/spdy/spdy_stream.h
index 402e892baeba2bb47c8adb21679527c10964036d..816c7bc825d3e63cdfcde4d550d89e193be470a4 100644
--- a/net/spdy/spdy_stream.h
+++ b/net/spdy/spdy_stream.h
@@ -372,6 +372,9 @@ class NET_EXPORT_PRIVATE SpdyStream {
   // GURL() if it is unknown.
   const GURL& GetUrlFromHeaders() const { return url_from_header_block_; }
 
+  // Returns the estimate of dynamically allocated memory in bytes.
+  size_t EstimateMemoryUsage() const;
+
  private:
   class HeadersBufferProducer;