Make UpgradeDetector work on the Mac

chrome/browser/cocoa/keystone_glue.h

 // 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.
 
 #ifndef CHROME_BROWSER_COCOA_KEYSTONE_GLUE_H_
 #define CHROME_BROWSER_COCOA_KEYSTONE_GLUE_H_
 
+#include "base/string16.h"
+
+#if defined(__OBJC__)
+
 #import <Foundation/Foundation.h>
-#import <base/scoped_nsobject.h>
 
+#import "base/scoped_nsobject.h"
 #include "chrome/browser/cocoa/scoped_authorizationref.h"
 
 // Possible outcomes of various operations.  A version may accompany some of
 // these, but beware: a version is never required.  For statuses that can be
 // accompanied by a version, the comment indicates what version is referenced.
 // A notification posted containing an asynchronous status will always be
 // followed by a notification with a terminal status.
 enum AutoupdateStatus {
   kAutoupdateNone = 0,        // no version (initial state only)
   kAutoupdateRegistering,     // no version (asynchronous operation in progress)
@@ skipping 160 matching lines @@
 - (void)stopTimer;
 
 // Called when a checkForUpdate: notification completes.
 - (void)checkForUpdateComplete:(NSNotification*)notification;
 
 // Called when an installUpdate: notification completes.
 - (void)installUpdateComplete:(NSNotification*)notification;
 
 @end  // @interface KeystoneGlue(ExposedForTesting)
 
+#endif  // __OBJC__
+
+// Functions that may be accessed from non-Objective-C C/C++ code.
+namespace keystone_glue {
+
+// True if Keystone is enabled.
+bool KeystoneEnabled();
+
+// The version of the application currently installed on disk.
+string16 CurrentlyInstalledVersion();
+
+}  // namespace keystone_glue
+
 #endif  // CHROME_BROWSER_COCOA_KEYSTONE_GLUE_H_