Improve memory estimate of SpdySessionPool in net/ MemoryDumpProvider.

net/spdy/hpack/hpack_header_table.cc

Index: net/spdy/hpack/hpack_header_table.cc
diff --git a/net/spdy/hpack/hpack_header_table.cc b/net/spdy/hpack/hpack_header_table.cc
index b005559415044107d25639885b6c8da303b85471..4da293c4d00140b3ca5956a01939cb5771844717 100644
--- a/net/spdy/hpack/hpack_header_table.cc
+++ b/net/spdy/hpack/hpack_header_table.cc
@@ -7,6 +7,7 @@
 #include <algorithm>
 
 #include "base/logging.h"
+#include "base/trace_event/memory_usage_estimator.h"
 #include "net/spdy/hpack/hpack_constants.h"
 #include "net/spdy/hpack/hpack_static_table.h"
 #include "net/spdy/spdy_flags.h"
@@ -274,4 +275,10 @@ void HpackHeaderTable::DebugLogTableState() const {
   }
 }
 
+size_t HpackHeaderTable::EstimateMemoryUsage() const {
+  return base::trace_event::EstimateMemoryUsage(dynamic_entries_) +
+         base::trace_event::EstimateMemoryUsage(dynamic_index_) +
+         base::trace_event::EstimateMemoryUsage(dynamic_name_index_);
+}
+
 }  // namespace net