base::mac::IsOSSierra() -> base::mac::IsOS10_12(), etc.

third_party/WebKit/Source/core/layout/LayoutThemeMac.mm

 /*
  * Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Google, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 238 matching lines @@
     fontStyle = ([fontManager traitsOfFont:font] & NSItalicFontMask) ? FontStyleItalic : FontStyleNormal;
     fontWeight = toFontWeight([fontManager weightOfFont:font]);
     fontSize = [font pointSize];
     fontFamily = @"BlinkMacSystemFont";
 }
 
 bool LayoutThemeMac::needsHackForTextControlWithFontFamily(const AtomicString& family) const
 {
     // This hack is only applied on OSX 10.9.
     // https://code.google.com/p/chromium/issues/detail?id=515989#c8
-    return IsOSMavericks() && family == "BlinkMacSystemFont";
+    return IsOS10_9() && family == "BlinkMacSystemFont";
 }
 
 static RGBA32 convertNSColorToColor(NSColor *color)
 {
     NSColor *colorInColorSpace = [color colorUsingColorSpaceName:NSDeviceRGBColorSpace];
     if (colorInColorSpace) {
         static const double scaleFactor = nextafter(256.0, 0.0);
         return makeRGB(static_cast<int>(scaleFactor * [colorInColorSpace redComponent]),
             static_cast<int>(scaleFactor * [colorInColorSpace greenComponent]),
             static_cast<int>(scaleFactor * [colorInColorSpace blueComponent]));
@@ skipping 201 matching lines @@
         if (style.effectiveZoom() != 1.0f)
             return true;
         if (!fontSizeMatchesToControlSize(style))
             return true;
         if (style.getFontDescription().family().family() != "BlinkMacSystemFont")
             return true;
         if (!style.height().isIntrinsicOrAuto())
             return true;
         // NSPopUpButtonCell on macOS 10.9 doesn't support
         // NSUserInterfaceLayoutDirectionRightToLeft.
-        if (IsOSMavericks() && style.direction() == RTL)
+        if (IsOS10_9() && style.direction() == RTL)
             return true;
     }
     // Some other cells don't work well when scaled.
     if (style.effectiveZoom() != 1) {
         switch (style.appearance()) {
         case ButtonPart:
         case PushButtonPart:
         case SearchFieldPart:
         case SquareButtonPart:
             return true;
@@ skipping 614 matching lines @@
 
 bool LayoutThemeMac::shouldUseFallbackTheme(const ComputedStyle& style) const
 {
     ControlPart part = style.appearance();
     if (part == CheckboxPart || part == RadioPart)
         return style.effectiveZoom() != 1;
     return false;
 }
 
 } // namespace blink