Add <stdarg.h> include required for va_start/va_end in GCC

Source/web/tests/WebFrameTest.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 103 matching lines @@
 #include "public/web/WebViewClient.h"
 #include "web/WebLocalFrameImpl.h"
 #include "web/WebRemoteFrameImpl.h"
 #include "web/WebViewImpl.h"
 #include "web/tests/FrameTestHelpers.h"
 #include "wtf/Forward.h"
 #include "wtf/dtoa/utils.h"
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 #include <map>
+#include <stdarg.h>
 #include <v8.h>
 
 using blink::URLTestHelpers::toKURL;
 using blink::FrameTestHelpers::UseMockScrollbarSettings;
 using blink::testing::runPendingTasks;
 using testing::ElementsAre;
 using ::testing::Mock;
 
 namespace blink {
 
@@ skipping 7592 matching lines @@
 TEST_F(WebFrameTest, OrientationFrameDetach)
 {
     RuntimeEnabledFeatures::setOrientationEventEnabled(true);
     registerMockedHttpURLLoad("orientation-frame-detach.html");
     FrameTestHelpers::WebViewHelper webViewHelper;
     WebViewImpl* webViewImpl = webViewHelper.initializeAndLoad(m_baseURL + "orientation-frame-detach.html", true);
     webViewImpl->mainFrameImpl()->sendOrientationChangeEvent();
 }
 
 } // namespace blink