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

ash/shell.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 "ash/shell.h"
 
 #include <algorithm>
 #include <string>
 #include <utility>
 
@@ skipping 781 matching lines @@
   const Config config = wm_shell_->GetConfig();
 
   blocking_pool_ = init_params.blocking_pool;
 
   wallpaper_delegate_ = shell_delegate_->CreateWallpaperDelegate();
 
   // Can be null in tests.
   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);
   }
 
   // Some delegates access WmShell during their construction. Create them here
   // instead of the WmShell constructor.
   accessibility_delegate_.reset(shell_delegate_->CreateAccessibilityDelegate());
   palette_delegate_ = shell_delegate_->CreatePaletteDelegate();
   toast_manager_ = base::MakeUnique<ToastManager>();
 
@@ skipping 439 matching lines @@
 
 void Shell::OnPrefServiceInitialized(
     std::unique_ptr<::PrefService> pref_service) {
   if (!instance_)
     return;
   DCHECK(pref_service);
   pref_service_ = std::move(pref_service);
 }
 
 }  // namespace ash