Remove the compile time flag for DATALIST Element.

Tools/DumpRenderTree/chromium/TestRunner/src/TestInterfaces.cpp

 /*
  * Copyright (C) 2012 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 66 matching lines @@
     WebRuntimeFeatures::enableGamepad(true);
     WebRuntimeFeatures::enableCustomDOMElements(true);
     WebRuntimeFeatures::enableStyleScoped(true);
     WebRuntimeFeatures::enableScriptedSpeech(true);
     WebRuntimeFeatures::enableRequestAutocomplete(true);
     WebRuntimeFeatures::enableExperimentalContentSecurityPolicyFeatures(true);
     WebRuntimeFeatures::enableSeamlessIFrames(true);
     WebRuntimeFeatures::enableCanvasPath(true);
     WebRuntimeFeatures::enableExperimentalShadowDOM(true);
     WebRuntimeFeatures::enableExperimentalCanvasFeatures(true);
+    WebRuntimeFeatures::enableDatalist(true);
 
     resetAll();
 }
 
 TestInterfaces::~TestInterfaces()
 {
     m_accessibilityController->setWebView(0);
     m_eventSender->setWebView(0);
     // m_gamepadController doesn't depend on WebView.
     m_textInputController->setWebView(0);
@@ skipping 125 matching lines @@
         m_themeEngine.reset(new WebTestThemeEngineWin());
     return m_themeEngine.get();
 #elif defined(__APPLE__)
     if (!m_themeEngine.get())
         m_themeEngine.reset(new WebTestThemeEngineMac());
     return m_themeEngine.get();
 #endif
 }
 
 }