Update from https://crrev.com/328418

base/mac/scoped_nsobject.h

 // 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.
 
 #ifndef BASE_MAC_SCOPED_NSOBJECT_H_
 #define BASE_MAC_SCOPED_NSOBJECT_H_
 
-#import <Foundation/Foundation.h>
+// Include NSObject.h directly because Foundation.h pulls in many dependencies.
+// (Approx 100k lines of code versus 1.5k for NSObject.h). scoped_nsobject gets
+// singled out because it is most typically included from other header files.
+#import <Foundation/NSObject.h>
+
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 
+@class NSAutoreleasePool;
+
 namespace base {
 
 // scoped_nsobject<> is patterned after scoped_ptr<>, but maintains ownership
 // of an NSObject subclass object.  Style deviations here are solely for
 // compatibility with scoped_ptr<>'s interface, with which everyone is already
 // familiar.
 //
 // scoped_nsobject<> takes ownership of an object (in the constructor or in
 // reset()) by taking over the caller's existing ownership claim.  The caller
 // must own the object it gives to scoped_nsobject<>, and relinquishes an
@@ skipping 140 matching lines @@
 template<>
 class scoped_nsobject<NSAutoreleasePool> {
  private:
   explicit scoped_nsobject(NSAutoreleasePool* object = nil);
   DISALLOW_COPY_AND_ASSIGN(scoped_nsobject);
 };
 
 }  // namespace base
 
 #endif  // BASE_MAC_SCOPED_NSOBJECT_H_