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

chrome/browser/ui/cocoa/toolbar/toolbar_controller.mm

 // Copyright (c) 2012 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/toolbar/toolbar_controller.h"
 
 #include <algorithm>
 
 #include "base/mac/bundle_locations.h"
 #include "base/mac/foundation_util.h"
@@ skipping 279 matching lines @@
 // reason is not guaranteed to be called (http://crbug.com/526276), so implement
 // both.
 - (void)awakeFromNib {
   [self viewDidLoad];
 }
 
 - (void)viewDidLoad {
   // When linking and running on 10.10+, both -awakeFromNib and -viewDidLoad may
   // be called, don't initialize twice.
   if (locationBarView_) {
-    DCHECK(base::mac::IsOSYosemiteOrLater());
+    DCHECK(base::mac::IsAtLeastOS10_10());
     return;
   }
 
   // Make Material Design layout adjustments to the NIB items.
   bool isModeMaterial = ui::MaterialDesignController::IsModeMaterial();
   if (isModeMaterial) {
     ToolbarView* toolbarView = [self toolbarView];
     NSRect toolbarBounds = [toolbarView bounds];
     NSSize toolbarButtonSize = [ToolbarButton toolbarButtonSize];
 
@@ skipping 875 matching lines @@
 - (void)hideDropURLsIndicatorInView:(NSView*)view {
   // Do nothing.
 }
 
 // (URLDropTargetController protocol)
 - (BOOL)isUnsupportedDropData:(id<NSDraggingInfo>)info {
   return drag_util::IsUnsupportedDropData(profile_, info);
 }
 
 @end