Pref service: have Mash and Chrome connect to the right pref stores

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index a0596e19a4fbfa7d47565d71157522ae5b830056..9d875b19bf0389e12d9f735ae1dfcfb9d1ab44e3 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -799,7 +799,7 @@ void Shell::Init(const ShellInitParams& init_params) {
   if (wm_shell_->IsRunningInMash() && shell_delegate_->GetShellConnector()) {
     prefs::ConnectToPrefService(
         shell_delegate_->GetShellConnector(),
-        make_scoped_refptr(new PrefRegistrySimple()),
+        make_scoped_refptr(new PrefRegistrySimple()), {},

[Bernhard Bauer, 2017/04/03 10:37:39]

Nit: Add a comment /* already_connected_types = */ before the argument?
Otherwise it's a bit hard to tell at a glance what that parameter is for.

[tibell, 2017/04/04 04:05:59]

I instead changed it to spell out the type, since {} doesn't work on all of our
compilers anyway. :/

[Bernhard Bauer, 2017/04/05 10:04:32]

:-/ An alternative might be to add a helper method named something like
NoPrefStoreTypes() that will return an empty vector.

[tibell, 2017/04/06 01:05:52]

I'm going to stick with what I have. This code is currently commented out in
HEAD due a ash vs Chrome startup ordering problem, otherwise I'd add a /* */
comment here, but you can't nest those. I will try to remember adding such a
comment back when we re-enable this code.

         base::Bind(&Shell::OnPrefServiceInitialized, base::Unretained(this)),
         prefs::mojom::kForwarderServiceName);
   }