Improve memory estimate of SpdySessionPool in net/ MemoryDumpProvider.

net/http2/hpack/decoder/hpack_decoder_string_buffer.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/http2/hpack/decoder/hpack_decoder_string_buffer.h"
 
 #include <utility>
 
 #include "base/logging.h"
+#include "base/trace_event/memory_usage_estimator.h"
 #include "net/http2/tools/http2_bug_tracker.h"
 
 using base::StringPiece;
 using std::string;
 
 namespace net {
 
 std::ostream& operator<<(std::ostream& out,
                          const HpackDecoderStringBuffer::State v) {
   switch (v) {
@@ skipping 197 matching lines @@
     out << ", is_huffman_encoded=" << is_huffman_encoded_;
     if (backing_ == Backing::BUFFERED) {
       out << ", buffer: " << buffer_;
     } else {
       out << ", value: " << value_;
     }
   }
   out << "}";
 }
 
+size_t HpackDecoderStringBuffer::EstimateMemoryUsage() const {
+  return base::trace_event::EstimateMemoryUsage(buffer_);
+}
+
 std::ostream& operator<<(std::ostream& out, const HpackDecoderStringBuffer& v) {
   v.OutputDebugStringTo(out);
   return out;
 }
 
 }  // namespace net