net: Add NET_API to url_request.

net/http/http_alternate_protocols.h

Index: net/http/http_alternate_protocols.h
===================================================================
--- net/http/http_alternate_protocols.h	(revision 85994)
+++ net/http/http_alternate_protocols.h	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 //
@@ -16,10 +16,11 @@
 
 #include "base/basictypes.h"
 #include "net/base/host_port_pair.h"
+#include "net/base/net_api.h"
 
 namespace net {
 
-class HttpAlternateProtocols {
+class NET_API HttpAlternateProtocols {
  public:
   enum Protocol {
     NPN_SPDY_1,