Reduce header dependencies in net/

TEST=none

Review URL: http://codereview.chromium.org/115870

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@17178 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/net/base/ssl_client_socket_nss.cc b/net/base/ssl_client_socket_nss.cc
index 12ef11e..ec2b961 100644
--- a/net/base/ssl_client_socket_nss.cc
+++ b/net/base/ssl_client_socket_nss.cc
@@ -66,6 +66,7 @@
 #include "base/logging.h"
 #include "base/nss_init.h"
 #include "base/string_util.h"
+#include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/base/ssl_info.h"