Improve memory estimate of SpdySessionPool in net/ MemoryDumpProvider.

net/spdy/header_coalescer.cc

 // Copyright (c) 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/spdy/header_coalescer.h"
 
 #include <utility>
 
 #include "base/strings/string_util.h"
+#include "net/spdy/platform/api/spdy_estimate_memory_usage.h"
 
 namespace net {
 
 const size_t kMaxHeaderListSize = 256 * 1024;
 
 void HeaderCoalescer::OnHeader(base::StringPiece key, base::StringPiece value) {
   if (error_seen_) {
     return;
   }
 
@@ skipping 43 matching lines @@
     headers_[key] = s;
   }
 }
 
 SpdyHeaderBlock HeaderCoalescer::release_headers() {
   DCHECK(headers_valid_);
   headers_valid_ = false;
   return std::move(headers_);
 }
 
+size_t HeaderCoalescer::EstimateMemoryUsage() const {
+  return SpdyEstimateMemoryUsage(headers_);
+}
+
 }  // namespace net