Improve memory estimate of SpdySessionPool in net/ MemoryDumpProvider.

net/spdy/spdy_stream.cc

Index: net/spdy/spdy_stream.cc
diff --git a/net/spdy/spdy_stream.cc b/net/spdy/spdy_stream.cc
index 126176d342f89539d55535127d60f2e2ac233774..3ae90e07417485d681ec11b277384f16090a94b3 100644
--- a/net/spdy/spdy_stream.cc
+++ b/net/spdy/spdy_stream.cc
@@ -18,6 +18,7 @@
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_task_runner_handle.h"
+#include "base/trace_event/memory_usage_estimator.h"
 #include "base/values.h"
 #include "net/log/net_log.h"
 #include "net/log/net_log_capture_mode.h"
@@ -819,6 +820,11 @@ bool SpdyStream::GetLoadTimingInfo(LoadTimingInfo* load_timing_info) const {
   return result;
 }
 
+size_t SpdyStream::EstimateMemoryUsage() const {
+  return base::trace_event::EstimateMemoryUsage(url_) +
+         base::trace_event::EstimateMemoryUsage(request_headers_);
+}
+
 void SpdyStream::UpdateHistograms() {
   // We need at least the receive timers to be filled in, as otherwise
   // metrics can be bogus.