Improve memory estimate of SpdySessionPool in net/ MemoryDumpProvider.

net/spdy/hpack/hpack_output_stream.cc

 // Copyright 2014 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/spdy/hpack/hpack_output_stream.h"
 
 #include <utility>
 
 #include "base/logging.h"
+#include "net/spdy/platform/api/spdy_estimate_memory_usage.h"
 
 namespace net {
 
 using base::StringPiece;
 using std::string;
 
 HpackOutputStream::HpackOutputStream() : bit_offset_(0) {}
 
 HpackOutputStream::~HpackOutputStream() {}
 
@@ skipping 65 matching lines @@
     // Give buffer to output string.
     *output = std::move(buffer_);
 
     // Reset to contain overflow.
     buffer_ = std::move(overflow);
   } else {
     TakeString(output);
   }
 }
 
+size_t HpackOutputStream::EstimateMemoryUsage() const {
+  return SpdyEstimateMemoryUsage(buffer_);
+}
+
 }  // namespace net