Provide lazy CommitPendingWrites in addition to eager SavePersistentPrefs.

chrome/browser/chromeos/cros/login_library.cc

Index: chrome/browser/chromeos/cros/login_library.cc
diff --git a/chrome/browser/chromeos/cros/login_library.cc b/chrome/browser/chromeos/cros/login_library.cc
index 026757f3b92226b9bdf99ae76e2eb3993e401f2f..7ee6f0ad07d243d783ea2b7e186d54a66d17030d 100644
--- a/chrome/browser/chromeos/cros/login_library.cc
+++ b/chrome/browser/chromeos/cros/login_library.cc
@@ -5,11 +5,14 @@
 #include "chrome/browser/chromeos/cros/login_library.h"
 
 #include "base/message_loop.h"
+#include "base/timer.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/cros/cros_library.h"
 #include "chrome/browser/chromeos/login/signed_settings_temp_storage.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "content/browser/browser_thread.h"
+#include "content/common/notification_observer.h"
+#include "content/common/notification_registrar.h"
 #include "content/common/notification_service.h"
 #include "content/common/notification_type.h"
 
@@ -131,16 +134,57 @@ class LoginLibraryImpl : public LoginLibrary {
   }
 
   bool RestartJob(int pid, const std::string& command_line) {
-    if (g_browser_process && g_browser_process->local_state()) {
-      // XXX: normally this call must not be needed, however it turned out that
-      // without this explicit call to SavePersistentPrefs it is possible for
-      // preferences to be lost. See http://crosbug.com/13102
-      g_browser_process->local_state()->SavePersistentPrefs();
-    }
-    return chromeos::RestartJob(pid, command_line.c_str());
+    job_restart_request_.reset(new JobRestartRequest(pid, command_line));
+    return true;
   }
 
  private:
+  class JobRestartRequest : public NotificationObserver {
+   public:
+    JobRestartRequest(int pid, const std::string& command_line)
+        : pid_(pid),
+          command_line_(command_line),
+          local_state_(g_browser_process->local_state()) {
+      if (local_state_) {
+        notification_registrar_.Add(this, NotificationType::PREF_COMMITTED,
+                                    Source<PrefService>(local_state_));
+        // XXX: normally this call must not be needed, however RestartJob
+        // just kills us so settings may be lost. See http://crosbug.com/13102
+        local_state_->CommitPendingWrite();
+        timer_.Start(
+            base::TimeDelta::FromSeconds(3), this,
+            &JobRestartRequest::RestartJob);
+      } else {
+        RestartJob();
+      }
+    }
+
+   private:
+    void RestartJob() {
+      if (!chromeos::RestartJob(pid_, command_line_.c_str()))
+        NOTREACHED();
+    }
+
+    // NotificationObserver implementation.
+    virtual void Observe(NotificationType type,
+                         const NotificationSource& source,
+                         const NotificationDetails& details) {
+      if (local_state_ &&
+          type.value == NotificationType::PREF_COMMITTED &&
+          source == Source<PrefService>(local_state_)) {
+        RestartJob();
+      } else {
+        NOTREACHED();
+      }
+    }
+
+    int pid_;
+    std::string command_line_;
+    NotificationRegistrar notification_registrar_;
+    PrefService* local_state_;
+    base::OneShotTimer<JobRestartRequest> timer_;
+  };
+
   static void Handler(void* object, const OwnershipEvent& event) {
     LoginLibraryImpl* self = static_cast<LoginLibraryImpl*>(object);
     switch (event) {
@@ -208,6 +252,7 @@ class LoginLibraryImpl : public LoginLibrary {
   }
 
   chromeos::SessionConnection session_connection_;
+  scoped_ptr<JobRestartRequest> job_restart_request_;
 
   Delegate* set_owner_key_callback_;
   Delegate* whitelist_op_callback_;