Improve memory estimate of SpdySessionPool in net/ MemoryDumpProvider.

net/spdy/hpack/hpack_decoder.cc

Index: net/spdy/hpack/hpack_decoder.cc
diff --git a/net/spdy/hpack/hpack_decoder.cc b/net/spdy/hpack/hpack_decoder.cc
index 575a5c19b715a25d0989b9048e808b137da3231c..78e1f18110747da703ba45e58df4fcf57cfa3f55 100644
--- a/net/spdy/hpack/hpack_decoder.cc
+++ b/net/spdy/hpack/hpack_decoder.cc
@@ -9,6 +9,7 @@
 #include "base/logging.h"
 #include "net/spdy/hpack/hpack_constants.h"
 #include "net/spdy/hpack/hpack_entry.h"
+#include "net/spdy/platform/api/spdy_estimate_memory_usage.h"
 #include "net/spdy/spdy_flags.h"
 
 namespace net {
@@ -116,6 +117,14 @@ void HpackDecoder::set_max_decode_buffer_size_bytes(
   max_decode_buffer_size_bytes_ = max_decode_buffer_size_bytes;
 }
 
+size_t HpackDecoder::EstimateMemoryUsage() const {
+  return SpdyEstimateMemoryUsage(header_table_) +
+         SpdyEstimateMemoryUsage(headers_block_buffer_) +
+         SpdyEstimateMemoryUsage(decoded_block_) +
+         SpdyEstimateMemoryUsage(key_buffer_) +
+         SpdyEstimateMemoryUsage(value_buffer_);
+}
+
 bool HpackDecoder::HandleHeaderRepresentation(StringPiece name,
                                               StringPiece value) {
   size_updates_allowed_ = false;