Mac: Remove some remaining 10.6 logic for absent overlay scrollbar APIs

third_party/WebKit/Source/platform/scroll/ScrollbarThemeMac.mm

 /*
  * Copyright (C) 2008, 2011 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 204 matching lines @@
     gPreferredScrollerStyle = preferredScrollerStyle;
     if (redraw && !scrollbarSet().isEmpty()) {
         ScrollbarSet::iterator end = scrollbarSet().end();
         for (ScrollbarSet::iterator it = scrollbarSet().begin(); it != end; ++it) {
             (*it)->styleChanged();
             (*it)->invalidate();
         }
     }
     if (sendScrollerStyleNotification) {
         [[NSNotificationCenter defaultCenter]
-            postNotificationName:@"NSPreferredScrollerStyleDidChangeNotification"
+            postNotificationName:NSPreferredScrollerStyleDidChangeNotification

[tapted, 2016/04/05 09:06:02]

nothing in blink seems to listen for this - maybe it's safe to just delete..

[Avi (use Gerrit), 2016/04/05 11:26:32]

delete away.

[Nico, 2016/04/05 12:30:30]

Does chrome do the right thing if you change the preferred scroller style in
sysprefs? (it used to, maybe someone broke that?)

[tapted, 2016/04/05 12:35:17]

Yup - the listener is at content/browser/theme_helper_mac.mm . That feeds
through a change from the browser process into blink, ending up in this method.
Currently, this method then re-broadcasts it, but nothing in blink's code is
subscribing to it.

[tapted, 2016/04/05 12:53:13]

Done.

                           object:nil
                         userInfo:@{ @"NSScrollerStyle" : @(gPreferredScrollerStyle) }];
     }
 }
 
 double ScrollbarThemeMac::initialAutoscrollTimerDelay()
 {
     return gInitialButtonDelay;
 }
 
@@ skipping 199 matching lines @@
 
 // static
 NSScrollerStyle ScrollbarThemeMac::recommendedScrollerStyle()
 {
     if (RuntimeEnabledFeatures::overlayScrollbarsEnabled())
         return NSScrollerStyleOverlay;
     return gPreferredScrollerStyle;
 }
 
 } // namespace blink