[Sync] Allow sync start without sign-in if the local sync backend is on.

chrome/browser/profiles/profile.cc

Index: chrome/browser/profiles/profile.cc
diff --git a/chrome/browser/profiles/profile.cc b/chrome/browser/profiles/profile.cc
index 65ac81bd893736a0a77146bb53e61eb02f41b803..f4a7b14795659cef407acc4a96da7f8d278334ca 100644
--- a/chrome/browser/profiles/profile.cc
+++ b/chrome/browser/profiles/profile.cc
@@ -211,9 +211,8 @@ bool Profile::IsNewProfile() {
 }
 
 bool Profile::IsSyncAllowed() {
-  if (ProfileSyncServiceFactory::HasProfileSyncService(this)) {
+  if (ProfileSyncServiceFactory::HasProfileSyncService(this))
     return ProfileSyncServiceFactory::GetForProfile(this)->IsSyncAllowed();
-  }
 
   // No ProfileSyncService created yet - we don't want to create one, so just
   // infer the accessible state by looking at prefs/command line flags.
@@ -222,6 +221,16 @@ bool Profile::IsSyncAllowed() {
          !prefs.IsManaged();
 }
 
+bool Profile::IsLocalSyncEnabled() {

[Nicolas Zea, 2016/12/15 00:37:28]

Do we really need this exposed here? Can we just have the callsites depend on
HasProfileSyncService directly?

[pastarmovj, 2016/12/16 17:04:48]

As suggested reverted this change.

+  if (ProfileSyncServiceFactory::HasProfileSyncService(this))
+    return ProfileSyncServiceFactory::GetForProfile(this)->IsLocalSyncEnabled();
+
+  // No ProfileSyncService created yet - we don't want to create one, so just
+  // infer the accessible state by looking at prefs/command line flags.
+  syncer::SyncPrefs prefs(GetPrefs());
+  return prefs.IsLocalSyncEnabled();
+}
+
 void Profile::MaybeSendDestroyedNotification() {
   if (!sent_destroyed_notification_) {
     sent_destroyed_notification_ = true;