Split out spdy_log_util from http_log_util.

net/spdy/spdy_log_util.cc

Index: net/spdy/spdy_log_util.cc
diff --git a/net/spdy/spdy_log_util.cc b/net/spdy/spdy_log_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..6f3d69104d63cd11788104712ae5219da3b26ff3
--- /dev/null
+++ b/net/spdy/spdy_log_util.cc
@@ -0,0 +1,40 @@
+// Copyright 2017 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/spdy_log_util.h"
+
+#include "base/memory/ptr_util.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/values.h"
+#include "net/http/http_log_util.h"
+
+namespace net {
+
+std::string ElideGoAwayDebugDataForNetLog(NetLogCaptureMode capture_mode,
+                                          base::StringPiece debug_data) {
+  // Note: this logic should be kept in sync with stripGoAwayDebugData in
+  // chrome/browser/resources/net_internals/log_view_painter.js.
+  if (capture_mode.include_cookies_and_credentials()) {
+    return debug_data.as_string();
+  }
+
+  return std::string("[") + base::SizeTToString(debug_data.size()) +
+         std::string(" bytes were stripped]");
+}
+
+std::unique_ptr<base::ListValue> ElideSpdyHeaderBlockForNetLog(
+    const SpdyHeaderBlock& headers,
+    NetLogCaptureMode capture_mode) {
+  auto headers_list = base::MakeUnique<base::ListValue>();
+  for (SpdyHeaderBlock::const_iterator it = headers.begin();
+       it != headers.end(); ++it) {
+    headers_list->AppendString(
+        it->first.as_string() + ": " +
+        ElideHeaderValueForNetLog(capture_mode, it->first.as_string(),
+                                  it->second.as_string()));
+  }
+  return headers_list;
+}
+
+}  // namespace net