arc: Support pinned apps across Arc-enabled and Arc-disabled platforms.

chrome/browser/ui/ash/chrome_launcher_prefs.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_ASH_CHROME_LAUNCHER_PREFS_H_
 #define CHROME_BROWSER_UI_ASH_CHROME_LAUNCHER_PREFS_H_
 
 #include <string>
 #include <vector>
 
 #include "ash/common/shelf/shelf_types.h"
 
 class LauncherControllerHelper;
 class PrefService;
+class Profile;
 
 namespace base {
 class DictionaryValue;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 namespace ash {
@@ skipping 31 matching lines @@
 
 // Get or set the shelf alignment preference for a particular display.
 ShelfAlignment GetShelfAlignmentPref(PrefService* prefs, int64_t display_id);
 void SetShelfAlignmentPref(PrefService* prefs,
                            int64_t display_id,
                            ShelfAlignment alignment);
 
 // Get the list of pinned apps from preferences.
 std::vector<std::string> GetPinnedAppsFromPrefs(
     const PrefService* prefs,
-    const LauncherControllerHelper* helper);
+    LauncherControllerHelper* helper);
+
+// Removes information about pin position from sync model for the app.
+void RemovePinPosition(Profile* profile, const std::string& app_id);
+
+// Updates information about pin position in sync model for the app |app_id|.
+// |app_id_before| optionally specifies an app that exists right before the
+// target app. |app_id_after| optionally specifies an app that exists right
+// after the target app.
+void SetPinPosition(Profile* profile,
+                    const std::string& app_id,
+                    const std::string& app_id_before,
+                    const std::string& app_id_after);

[stevenjb, 2016/06/10 18:00:41]

These functions should really all be in a separate namespace, e.g.
ash::launcher. 'ash' is very large and the context of 'SetPinPosition' is not
necessarily obvious.

[khmel, 2016/06/10 22:08:11]

Done.

 
 }  // namespace ash
 
 #endif  // CHROME_BROWSER_UI_ASH_CHROME_LAUNCHER_PREFS_H_