Replace hide-scrollbars flag with a web setting.

third_party/WebKit/Source/core/testing/InternalSettings.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 124 matching lines @@
         return 0;
     return &page()->settings();
 }
 
 void InternalSettings::setMockScrollbarsEnabled(bool enabled, ExceptionState& exceptionState)
 {
     InternalSettingsGuardForSettings();
     settings()->setMockScrollbarsEnabled(enabled);
 }
 
+void InternalSettings::setHideScrollbars(bool enabled, ExceptionState& exceptionState)
+{
+    InternalSettingsGuardForSettings();
+    settings()->setHideScrollbars(enabled);
+}
+
 void InternalSettings::setMockGestureTapHighlightsEnabled(bool enabled, ExceptionState& exceptionState)
 {
     InternalSettingsGuardForSettings();
     settings()->setMockGestureTapHighlightsEnabled(enabled);
 }
 
 void InternalSettings::setCSSStickyPositionEnabled(bool enabled)
 {
     RuntimeEnabledFeatures::setCSSStickyPositionEnabled(enabled);
 }
@@ skipping 321 matching lines @@
     settings()->setLogPreload(enabled);
 }
 
 void InternalSettings::setCompositorWorkerEnabled(bool enabled, ExceptionState& exceptionState)
 {
     InternalSettingsGuardForSettings();
     RuntimeEnabledFeatures::setCompositorWorkerEnabled(enabled);
 }
 
 } // namespace blink