Replace hide-scrollbars flag with a web setting.

third_party/WebKit/Source/web/WebRuntimeFeatures.cpp

 /*
  * 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 272 matching lines @@
 void WebRuntimeFeatures::enableXSLT(bool enable)
 {
     RuntimeEnabledFeatures::setXSLTEnabled(enable);
 }
 
 void WebRuntimeFeatures::enableOverlayScrollbars(bool enable)
 {
     RuntimeEnabledFeatures::setOverlayScrollbarsEnabled(enable);
 }
 
-void WebRuntimeFeatures::enableHideScrollbars(bool enable)
-{
-    RuntimeEnabledFeatures::setHideScrollbarsEnabled(enable);
-}
-
 void WebRuntimeFeatures::forceOverlayFullscreenVideo(bool enable)
 {
     RuntimeEnabledFeatures::setForceOverlayFullscreenVideoEnabled(enable);
 }
 
 void WebRuntimeFeatures::enableSharedWorker(bool enable)
 {
     RuntimeEnabledFeatures::setSharedWorkerEnabled(enable);
 }
 
@@ skipping 96 matching lines @@
 {
     RuntimeEnabledFeatures::setTimerThrottlingForHiddenFramesEnabled(enable);
 }
 
 void WebRuntimeFeatures::enableSendBeaconThrowForBlobWithNonSimpleType(bool enable)
 {
     RuntimeEnabledFeatures::setSendBeaconThrowForBlobWithNonSimpleTypeEnabled(enable);
 }
 
 } // namespace blink