Address post-submit comments from http://codereview.chromium.org/327009 .

chrome/browser/cocoa/repost_form_warning_mac.mm

 // Copyright (c) 2009 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.
 
 #include "chrome/browser/cocoa/repost_form_warning_mac.h"
 
 #include "app/l10n_util_mac.h"
 #include "base/message_loop.h"
 #include "chrome/browser/tab_contents/navigation_controller.h"
 #include "chrome/common/notification_service.h"
 #include "grit/generated_resources.h"
 
+// The delegate of the NSAlert used to display the dialog. Forwards the alert's
+// completion event to the C++ class |RepostFormWarningMac|.
+@interface RepostDelegate : NSObject {
+  RepostFormWarningMac* warning_;  // weak, owns us.
+}
+- (id)initWithWarning:(RepostFormWarningMac*)warning;
+- (void)alertDidEnd:(NSAlert*)alert
+         returnCode:(int)returnCode
+        contextInfo:(void*)contextInfo;
+@end
+
 @implementation RepostDelegate
 - (id)initWithWarning:(RepostFormWarningMac*)warning {
   if ((self = [super init])) {
     warning_ = warning;
   }
   return self;
 }
 
 - (void)alertDidEnd:(NSAlert*)alert
          returnCode:(int)returnCode
@@ skipping 61 matching lines @@
     [NSApp endSheet:[alert_ window] returnCode:NSAlertSecondButtonReturn];
   }
 }
 
 void RepostFormWarningMac::Destroy() {
   if (alert_) {
     alert_.reset(NULL);
     MessageLoop::current()->DeleteSoon(FROM_HERE, this);
   }
 }