Make file IO occur on the right thread.

chrome/browser/chromeos/system/timezone_settings.cc

Index: chrome/browser/chromeos/system/timezone_settings.cc
diff --git a/chrome/browser/chromeos/system/timezone_settings.cc b/chrome/browser/chromeos/system/timezone_settings.cc
index 03703a98fee07b975b5d8e7a1b35e4fbaf98ef5e..bda09f80b7f7629ce33906f56dca50745fa997ad 100644
--- a/chrome/browser/chromeos/system/timezone_settings.cc
+++ b/chrome/browser/chromeos/system/timezone_settings.cc
@@ -12,6 +12,7 @@
 #include "base/memory/singleton.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
+#include "content/browser/browser_thread.h"
 
 namespace chromeos {
 namespace system {
@@ -120,7 +121,9 @@ void TimezoneSettingsImpl::SetTimezone(const icu::TimeZone& timezone) {
   std::string id;
   UTF16ToUTF8(unicode.getBuffer(), unicode.length(), &id);
   VLOG(1) << "Setting timezone to " << id;
-  SetTimezoneIDFromString(id);
+  BrowserThread::PostTask(BrowserThread::FILE,

[satorux1, 2011/09/19 16:49:03]

I think it's safe to do SetTimezoneIDFromString() in the background, but this is
a bit tricky. Would be nice to add a comment like

Change the timezone config files in the FILE thread. It's safe to do this in the
background as the following operations don't depend on the completion of the
config change.

[pastarmovj, 2011/09/20 12:04:12]

Done.

+                          FROM_HERE,
+                          NewRunnableFunction(&SetTimezoneIDFromString, id));

[satorux1, 2011/09/19 16:49:03]

Can you use base::Bind() instead? NewRunnableFunction is now deprecated.

[pastarmovj, 2011/09/20 12:04:12]

Done.

   icu::TimeZone::setDefault(timezone);
   FOR_EACH_OBSERVER(Observer, observers_, TimezoneChanged(timezone));
 }