net: Add NET_API to net/base

net/base/keygen_handler.h

Index: net/base/keygen_handler.h
===================================================================
--- net/base/keygen_handler.h	(revision 85332)
+++ net/base/keygen_handler.h	(working copy)
@@ -11,6 +11,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "build/build_config.h"
 #include "googleurl/src/gurl.h"
+#include "net/base/net_api.h"
 
 #if defined(USE_NSS)
 #include "crypto/crypto_module_blocking_password_delegate.h"
@@ -23,7 +24,7 @@
 // <http://dev.w3.org/html5/spec/Overview.html#the-keygen-element>
 // <https://developer.mozilla.org/En/HTML/HTML_Extensions/KEYGEN_Tag>
 
-class KeygenHandler {
+class NET_API KeygenHandler {
  public:
   // Creates a handler that will generate a key with the given key size and
   // incorporate the |challenge| into the Netscape SPKAC structure. The request