startup: Put it in chrome namespace.

chrome/browser/ui/cocoa/obsolete_os.h

Index: chrome/browser/ui/cocoa/obsolete_os.h
diff --git a/chrome/browser/ui/cocoa/obsolete_os.h b/chrome/browser/ui/cocoa/obsolete_os.h
index 5f1022cd99819169c6590baa01285683b2815d4f..cb1c6fcf6c4a38cda45839e7eea56c3f573dfa29 100644
--- a/chrome/browser/ui/cocoa/obsolete_os.h
+++ b/chrome/browser/ui/cocoa/obsolete_os.h
@@ -9,7 +9,7 @@
 #include "base/mac/mac_util.h"
 #include "base/string16.h"
 
-namespace browser {
+namespace chrome {
 
 // Returns true if the OS will either be unsupported by future versions of the
 // application in the near future, or if this is the last version of the
@@ -25,6 +25,6 @@ inline bool IsOSObsoleteOrNearlySo() {
 // true.
 string16 LocalizedObsoleteOSString();
 
-}  // namespace browser
+}  // namespace chrome
 
 #endif  // CHROME_BROWSER_UI_COCOA_OBSOLETE_OS_H_