Update from https://crrev.com/328418

base/mac/scoped_nsobject.h

Index: base/mac/scoped_nsobject.h
diff --git a/base/mac/scoped_nsobject.h b/base/mac/scoped_nsobject.h
index 8814b51439b6f76e96e3e235bb620438009cdc50..836bdcc35071aa5f92de20972b9685037c11afa4 100644
--- a/base/mac/scoped_nsobject.h
+++ b/base/mac/scoped_nsobject.h
@@ -5,10 +5,16 @@
 #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