Migrate WTF::HashMap::get() to ::at()

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 226 matching lines @@
       [[BlinkScrollbarObserver alloc] initWithScrollbar:&scrollbar
                                                 painter:scrollbarPainter]);
   scrollbarPainterMap().set(&scrollbar, observer);
   updateEnabledState(scrollbar);
   updateScrollbarOverlayColorTheme(scrollbar);
 }
 
 ScrollbarPainter ScrollbarThemeMac::painterForScrollbar(
     const ScrollbarThemeClient& scrollbar) const {
   return [scrollbarPainterMap()
-              .get(const_cast<ScrollbarThemeClient*>(&scrollbar))
+              .at(const_cast<ScrollbarThemeClient*>(&scrollbar))
               .get() painter];
 }
 
 void ScrollbarThemeMac::paintTrackBackground(GraphicsContext& context,
                                              const Scrollbar& scrollbar,
                                              const IntRect& rect) {
   if (DrawingRecorder::useCachedDrawingIfPossible(
           context, scrollbar, DisplayItem::kScrollbarTrackBackground))
     return;
 
@@ skipping 151 matching lines @@
 }
 
 // static
 NSScrollerStyle ScrollbarThemeMac::recommendedScrollerStyle() {
   if (RuntimeEnabledFeatures::overlayScrollbarsEnabled())
     return NSScrollerStyleOverlay;
   return gPreferredScrollerStyle;
 }
 
 }  // namespace blink