Ensure Sync access token is revoked when user is signed out.

components/browser_sync/browser/profile_sync_service.cc

Index: components/browser_sync/browser/profile_sync_service.cc
diff --git a/components/browser_sync/browser/profile_sync_service.cc b/components/browser_sync/browser/profile_sync_service.cc
index 4ace5233f866735c2c165ea4f19d5ee831f13053..d10bbf9b50261510b43b6e991c505e15eb76fca5 100644
--- a/components/browser_sync/browser/profile_sync_service.cc
+++ b/components/browser_sync/browser/profile_sync_service.cc
@@ -765,7 +765,8 @@ void ProfileSyncService::OnRefreshTokenAvailable(
 
 void ProfileSyncService::OnRefreshTokenRevoked(
     const std::string& account_id) {
-  if (account_id == signin_->GetAccountIdToUse()) {
+  if (account_id == signin_->GetAccountIdToUse() ||
+      !signin_->GetOriginal()->IsAuthenticated()) {

[Nicolas Zea, 2015/12/02 18:57:35]

Is this the right place to fix this? Why isn't the first condition sufficient?
It seems like the refresh token should be revoked when you switch accounts,
right?

[bzanotti, 2015/12/02 22:21:46]

Please note that I'm not super familiar with sync code, I was just trying to
reintroduce the same logic that was removed in http://crrev.com/1354053004
without reintroducing the bug.

Maybe this is not the best place to fix this, but note that due to how signout
works, this notification is received before the OnGoogleSignOut notification
(but SigninManager will already return false to IsAuthenticated).

Maybe the access_token should simply be cleared on signout (I have no idea why
this isn't the case, but I can observe this on iOS). If you have more
information/context on this, I'm very interested.

[Nicolas Zea, 2015/12/02 22:27:54]

Yeah, I think that OnGoogleSignedOut should also be clearing the access_token_
(and calling the UpdateAuthErrorState). That seems a more natural fit for this
logic, and I agree it seems wrong that wasn't happening before.

     access_token_.clear();
     UpdateAuthErrorState(
         GoogleServiceAuthError(GoogleServiceAuthError::REQUEST_CANCELED));