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

chrome/browser/ui/cocoa/browser_window_layout.mm

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/ui/cocoa/browser_window_layout.h"
 
 #include <math.h>
 #include <string.h>
 
 #include "base/logging.h"
@@ skipping 43 matching lines @@
 // Computes the height of the backing bar for the views in the omnibox area in
 // fullscreen mode.
 - (CGFloat)fullscreenBackingBarHeight;
 
 @end
 
 @implementation BrowserWindowLayout
 
 - (instancetype)init {
   if ((self = [super init])) {
-    parameters_.isOSYosemiteOrLater = base::mac::IsOSYosemiteOrLater();
+    parameters_.isOSYosemiteOrLater = base::mac::IsAtLeastOS10_10();
   }
   return self;
 }
 
 - (chrome::LayoutOutput)computeLayout {
   memset(&output_, 0, sizeof(chrome::LayoutOutput));
 
   [self computeFullscreenYOffset];
   [self computeTabStripLayout];
   [self computeContentViewLayout];
@@ skipping 320 matching lines @@
 
 @end
 
 @implementation BrowserWindowLayout (ExposedForTesting)
 
 - (void)setOSYosemiteOrLater:(BOOL)osYosemiteOrLater {
   parameters_.isOSYosemiteOrLater = osYosemiteOrLater;
 }
 
 @end