Avoid a crash in ProfileManager::GetLastUsedProfileAllowedByPolicy()

chrome/browser/profiles/profile_manager.cc

Index: chrome/browser/profiles/profile_manager.cc
diff --git a/chrome/browser/profiles/profile_manager.cc b/chrome/browser/profiles/profile_manager.cc
index becbbe83f74e625e94b16b4d14f564f08908a07e..1cfc620eedaf53b5c74ea52a6c12d04fe4adcd38 100644
--- a/chrome/browser/profiles/profile_manager.cc
+++ b/chrome/browser/profiles/profile_manager.cc
@@ -371,6 +371,8 @@ Profile* ProfileManager::GetLastUsedProfile() {
 // static
 Profile* ProfileManager::GetLastUsedProfileAllowedByPolicy() {
   Profile* profile = GetLastUsedProfile();
+  if (!profile)
+    return nullptr;
   if (IncognitoModeForced(profile))
     return profile->GetOffTheRecordProfile();
   return profile;