Add enable*Features functions in preparation for using them in content.

Source/WebKit/chromium/public/WebRuntimeFeatures.h

 /*
  * Copyright (C) 2009 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 23 matching lines @@
 #include "../../../Platform/chromium/public/WebCommon.h"
 
 namespace WebKit {
 
 // This class is used to enable runtime features of WebKit.  It is unspecified
 // whether a feature is enabled by default.  In the future, a feature may be
 // promoted from disabled by default to enabled by default once it reaches a
 // certain level of maturity.
 class WebRuntimeFeatures {
 public:
+    WEBKIT_EXPORT static void enableStableFeatures(bool);
+    WEBKIT_EXPORT static void enableExperimentalFeatures(bool);
+    WEBKIT_EXPORT static void enableTestOnlyFeatures(bool);
+
     WEBKIT_EXPORT static void enableDatabase(bool);
     WEBKIT_EXPORT static bool isDatabaseEnabled();
 
     WEBKIT_EXPORT static void enableLocalStorage(bool);
     WEBKIT_EXPORT static bool isLocalStorageEnabled();
 
     WEBKIT_EXPORT static void enableSessionStorage(bool);
     WEBKIT_EXPORT static bool isSessionStorageEnabled();
 
     WEBKIT_EXPORT static void enableMediaPlayer(bool);
@@ skipping 128 matching lines @@
     WEBKIT_EXPORT static void enableSpeechSynthesis(bool);
     WEBKIT_EXPORT static bool isSpeechSynthesisEnabled();
 
 private:
     WebRuntimeFeatures();
 };
 
 } // namespace WebKit
 
 #endif