Use IsSigninProfile instead.

This is just code cleanup, IsSigninProfile does the same thing. This affects chromeos only.

BUG=
TBR=skuhne@chromium.org

Review-Url: https://codereview.chromium.org/2149603003
Cr-Commit-Position: refs/heads/master@{#405227}

chrome/browser/profiles/profile_manager.cc

@@ -1492,9 +1492,8 @@ void ProfileManager::SetNonPersonalProfilePrefs(Profile* profile) {
 
 bool ProfileManager::ShouldGoOffTheRecord(Profile* profile) {
 #if defined(OS_CHROMEOS)
-  if (profile->GetPath().BaseName().value() == chrome::kInitialProfile) {
+  if (chromeos::ProfileHelper::IsSigninProfile(profile))
     return true;
-  }
 #endif
   return profile->IsGuestSession() || profile->IsSystemProfile();
 }