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

chrome/browser/resources/net_export/net_export.css

Index: chrome/browser/resources/net_export/net_export.css
===================================================================
--- chrome/browser/resources/net_export/net_export.css	(revision 0)
+++ chrome/browser/resources/net_export/net_export.css	(revision 0)
@@ -0,0 +1,22 @@
+/* Copyright (c) 2013 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.
+ */
+
+body {
+  font-family: sans-serif;
+  font-size: 80%;
+}
+
+button {
+  font-size: 100%;
+  font-weight: bold;
+}
+
+.warning {
+  color: red;
+}
+
+#net-export-main {
+  margin: 8px;
+}