Remove HasBeenShutdown check on iOS for the sign-in confirmation.

BUG=405048

Review URL: https://codereview.chromium.org/546343004

Cr-Commit-Position: refs/heads/master@{#293882}

chrome/browser/ui/sync/profile_signin_confirmation_helper.cc

@@ -38,7 +38,7 @@ const int kHistoryEntriesBeforeNewProfilePrompt = 10;
 // Determines whether a profile has any typed URLs in its history.
 class HasTypedURLsTask : public history::HistoryDBTask {
  public:
-  HasTypedURLsTask(const base::Callback<void(bool)>& cb)
+  explicit HasTypedURLsTask(const base::Callback<void(bool)>& cb)
       : has_typed_urls_(false), cb_(cb) {
   }
 
@@ -189,10 +189,19 @@ SkColor GetSigninConfirmationPromptBarColor(SkAlpha alpha) {
 }
 
 bool HasBeenShutdown(Profile* profile) {
+#if defined(OS_IOS)
+  // This check is not useful on iOS: the browser can be shut down without
+  // explicit user action (for example, in response to memory pressure), and
+  // this should be invisible to the user. The desktop assumption that the
+  // profile going through a restart indicates something about user intention
+  // does not hold. We rely on the other profile dirtiness checks.
+  return false;
+#else
   bool has_been_shutdown = !profile->IsNewProfile();
   if (has_been_shutdown)
     DVLOG(1) << "ProfileSigninConfirmationHelper: profile is not new";
   return has_been_shutdown;
+#endif
 }
 
 bool HasSyncedExtensions(Profile* profile) {