Replace direct access to kGoogleServicesUsername with calls to SigninManager.

chrome/browser/sync/profile_sync_service.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/sync/profile_sync_service.h"
 
 #include <cstddef>
 #include <map>
 #include <vector>
 
@@ skipping 2483 matching lines @@
 
 SigninManagerBase* ProfileSyncService::signin() const {
   if (!signin_)
     return NULL;
   return signin_->GetOriginal();
 }
 
 void ProfileSyncService::UnsuppressAndStart() {
   DCHECK(profile_);
   sync_prefs_.SetStartSuppressed(false);
-  if (signin_.get() && !signin_->GetOriginal()->IsAuthenticated()) {
-    signin_->GetOriginal()->SetAuthenticatedUsername(
-        profile_->GetPrefs()->GetString(prefs::kGoogleServicesUsername));

[Nicolas Zea, 2014/12/04 17:57:39]

Is this no longer necessary? Was the signin manager previously not always fully
initialized, but it is now?

[Roger Tawa OOO till Jul 10th, 2014/12/04 22:26:47]

Well, that's a question for you :-)  Pavel tracked down the introduction of this
to an old CL:

https://codereview.chromium.org/8332023/diff/8002/chrome/browser/sync/profile...

but the comment is no longer applicable.  Today, if you look at the
implementation of signin_->GetOriginal()->IsAuthenticated(), that is true iff
!authenticated_account_id_.empty().  That member is initialized either from:

1/ prefs::kGoogleServicesUsername, OR
2/ by a call to SetAuthenticatedUsername(), which sets
prefs::kGoogleServicesUsername

So if IsAuthenticated() is false, then prefs::kGoogleServicesUsername is empty,
and SetAuthenticatedUsername() would DCHECK.

I left a DCHECK to see if my assumption is wrong, but it was not hit in any of
the unit tests or browser tests, or in any of the manual testing I did.

-  }
+  DCHECK(!signin_.get() || signin_->GetOriginal()->IsAuthenticated());
   startup_controller_.TryStart();
 }
 
 void ProfileSyncService::AcknowledgeSyncedTypes() {
   sync_prefs_.AcknowledgeSyncedTypes(GetRegisteredDataTypes());
 }
 
 void ProfileSyncService::ReconfigureDatatypeManager() {
   // If we haven't initialized yet, don't configure the DTM as it could cause
   // association to start before a Directory has even been created.
@@ skipping 244 matching lines @@
 
 base::MessageLoop* ProfileSyncService::GetSyncLoopForTest() const {
   if (sync_thread_) {
     return sync_thread_->message_loop();
   } else if (backend_) {
     return backend_->GetSyncLoopForTesting();
   } else {
     return NULL;
   }
 }