Mac: Remove use of deprecated [NSNib instantiateNibWithOwner:topLevelObjects:].

ui/base/cocoa/nib_loading.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 "ui/base/cocoa/nib_loading.h"
 
 #include "base/mac/bundle_locations.h"
 #include "base/mac/scoped_nsobject.h"
 
+@interface NSNib (MountainLionSDK)
+- (BOOL)instantiateWithOwner:(nullable id)owner
+             topLevelObjects:(NSArray* __nonnull* __nullable)topLevelObjects;
+@end
+
 namespace ui {
 
 NSView* GetViewFromNib(NSString* name) {
   base::scoped_nsobject<NSNib> nib(
       [[NSNib alloc] initWithNibNamed:name
                                bundle:base::mac::FrameworkBundle()]);
   if (!nib)
     return nil;
 
   NSArray* objects;
-  BOOL success = [nib instantiateNibWithOwner:nil
-                              topLevelObjects:&objects];
+  BOOL success = [nib instantiateWithOwner:nil topLevelObjects:&objects];
   if (!success)
     return nil;
 
-  // When loading a nib manually (as opposed to using an NSWindowController or
-  // NSViewController), all the top-level objects need to be explicitly
-  // released. See
-  // http://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/LoadingResources/CocoaNibs/CocoaNibs.html#//apple_ref/doc/uid/10000051i-CH4-SW10
-  // for more information.
-  [objects makeObjectsPerformSelector:@selector(release)];
-
   // For some strange reason, even nibs that appear to have but one top-level
   // object often have more (an NSApplication, etc.). Filter out what isn't
   // desired.
   for (NSView* view in objects) {
     if (![view isKindOfClass:[NSView class]])
       continue;
 
     return [[view retain] autorelease];
   }
 
   return nil;
 }
 
 }  // namespace ui