Switch to standard integer types in ppapi/.

ppapi/tests/extensions/background_keepalive/background.cc

 // 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.
 
+#include <stdint.h>
+
 #include <cstdio>
 #include <string>
 
 #include "ppapi/cpp/instance.h"
 #include "ppapi/cpp/message_loop.h"
 #include "ppapi/cpp/module.h"
 #include "ppapi/cpp/var.h"
 #include "ppapi/utility/completion_callback_factory.h"
 
 class Instance : public pp::Instance {
@@ skipping 39 matching lines @@
     return new Instance(instance);
   }
 };
 
 namespace pp {
 Module* CreateModule() {
   return new ::Module();
 }
 }  // namespace pp