First cut at UI for saving net_logs data into a temporary file on

chrome/browser/net/net_log_logger.cc

 // Copyright (c) 2012 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 "chrome/browser/net/net_log_logger.h"
 
 #include <stdio.h>
 
 #include "base/file_util.h"
 #include "base/json/json_writer.h"
@@ skipping 25 matching lines @@
   }
 }
 
 NetLogLogger::~NetLogLogger() {
 }
 
 void NetLogLogger::StartObserving(net::NetLog* net_log) {
   net_log->AddThreadSafeObserver(this, net::NetLog::LOG_ALL_BUT_BYTES);
 }
 
+void NetLogLogger::StopObserving() {
+  net_log()->RemoveThreadSafeObserver(this);
+}
+
 void NetLogLogger::OnAddEntry(const net::NetLog::Entry& entry) {
   scoped_ptr<Value> value(entry.ToValue());
   // Don't pretty print, so each JSON value occupies a single line, with no
   // breaks (Line breaks in any text field will be escaped).  Using strings
   // instead of integer identifiers allows logs from older versions to be
   // loaded, though a little extra parsing has to be done when loading a log.
   std::string json;
   base::JSONWriter::Write(value.get(), &json);
   if (!file_.get()) {
     VLOG(1) << json;
   } else {
     fprintf(file_.get(), "%s,\n", json.c_str());
   }
 }