Improve memory estimate of SpdySessionPool in net/ MemoryDumpProvider.

net/spdy/hpack/hpack_decoder_interface.h

Index: net/spdy/hpack/hpack_decoder_interface.h
diff --git a/net/spdy/hpack/hpack_decoder_interface.h b/net/spdy/hpack/hpack_decoder_interface.h
index 1103e3198fb0b1d2b0205eb3fbfb131c298122ad..375e22145089619fccf352d0faa384c5571f7afb 100644
--- a/net/spdy/hpack/hpack_decoder_interface.h
+++ b/net/spdy/hpack/hpack_decoder_interface.h
@@ -66,6 +66,9 @@ class NET_EXPORT_PRIVATE HpackDecoderInterface {
   // of individual transport buffers.
   virtual void set_max_decode_buffer_size_bytes(
       size_t max_decode_buffer_size_bytes) = 0;
+
+  // Returns the estimate of dynamically allocated memory in bytes.
+  virtual size_t EstimateMemoryUsage() const = 0;
 };
 
 }  // namespace net