Remove use of <iostream> where unnecessary.

ppapi/native_client/tests/ppapi_simple_tests/file.cc

 // Copyright (c) 2011 The Native Client 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 <stdint.h>
 #include <stdlib.h>
 
-#include <iostream>
+#include <ostream>
 #include <sstream>
 #include <string>
 #include <queue>
 
 #include <nacl/nacl_check.h>
 
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/ppb_file_io.h"
 
 #include "ppapi/cpp/completion_callback.h"
@@ skipping 297 matching lines @@
   virtual pp::Instance* CreateInstance(PP_Instance instance) {
     return new MyInstance(instance);
   }
 };
 
 namespace pp {
   Module* CreateModule() {
     return new MyModule();
   }
 }