Remove unused WebRuntimeFeatures::enableStableFeatures

public/web/WebRuntimeFeatures.h

 /*
  * Copyright (C) 2013 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 18 matching lines @@
  */
 
 #ifndef WebRuntimeFeatures_h
 #define WebRuntimeFeatures_h
 
 #include "public/platform/WebCommon.h"
 
 namespace blink {
 
 // This class is used to enable runtime features of Blink.
-// All features are disabled by default.
-// Most clients should call enableStableFeatures() to enable
-// features Blink has made API commitments to.
+// Stable features are enabled by default.
 class WebRuntimeFeatures {
 public:
-    BLINK_EXPORT static void enableStableFeatures(bool);
     BLINK_EXPORT static void enableExperimentalFeatures(bool);
     BLINK_EXPORT static void enableTestOnlyFeatures(bool);
 
     BLINK_EXPORT static void enableApplicationCache(bool);
 
     BLINK_EXPORT static void enableDatabase(bool);
 
     BLINK_EXPORT static void enableDialogElement(bool);
 
     BLINK_EXPORT static void enableEncryptedMedia(bool);
@@ skipping 77 matching lines @@
 
     BLINK_EXPORT static void enableTargetedStyleRecalc(bool);
 
 private:
     WebRuntimeFeatures();
 };
 
 } // namespace blink
 
 #endif