Mac: reform our shutdown routine.

chrome/browser/chrome_browser_application_mac.h

-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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 CHROME_BROWSER_CHROME_BROWSER_APPLICATION_MAC_H_
 #define CHROME_BROWSER_CHROME_BROWSER_APPLICATION_MAC_H_
 
 #ifdef __OBJC__
 
 #import "base/chrome_application_mac.h"
 
 @interface BrowserCrApplication : CrApplication
+// Our implementation of |-terminate:| only attempts to terminate the
+// application, i.e., begins a process which may lead to termination. This
+// method cancels that process.
+- (void)cancelTerminate:(id)sender;
 @end
 
 namespace chrome_browser_application_mac {
 
 // Bin for unknown exceptions. Exposed for testing purposes.
 extern const size_t kUnknownNSException;
 
 // Returns the histogram bin for |exception| if it is one we track
 // specifically, or |kUnknownNSException| if unknown.  Exposed for testing
 // purposes.
 size_t BinForException(NSException* exception);
 
 // Use UMA to track exception occurance. Exposed for testing purposes.
 void RecordExceptionWithUma(NSException* exception);
 
 }  // namespace chrome_browser_application_mac
 
 #endif  // __OBJC__
 
 namespace chrome_browser_application_mac {
 
 // Calls -[NSApp terminate:].
 void Terminate();
 
+// Cancels a termination started by |Terminate()|.
+void CancelTerminate();
+
 }  // namespace chrome_browser_application_mac
 
 #endif  // CHROME_BROWSER_CHROME_BROWSER_APPLICATION_MAC_H_