Add a policy to always show the Cast toolbar icon

chrome/browser/ui/toolbar/media_router_action_controller.h

 // Copyright 2016 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_TOOLBAR_MEDIA_ROUTER_ACTION_CONTROLLER_H_
 #define CHROME_BROWSER_UI_TOOLBAR_MEDIA_ROUTER_ACTION_CONTROLLER_H_
 
 #include <vector>
 
 #include "chrome/browser/extensions/component_migration_helper.h"
 #include "chrome/browser/media/router/issues_observer.h"
 #include "chrome/browser/media/router/media_routes_observer.h"
 #include "chrome/browser/profiles/profile.h"
 #include "components/prefs/pref_change_registrar.h"
+#include "components/user_prefs/user_prefs.h"
 
 using extensions::ComponentMigrationHelper;
 
 // Controller for MediaRouterAction that determines when to show and hide the
 // action icon on the toolbar. There should be one instance of this class per
 // profile, and it should only be used on the UI thread.
 class MediaRouterActionController : public media_router::IssuesObserver,
                                     public media_router::MediaRoutesObserver {
  public:
   explicit MediaRouterActionController(Profile* profile);
   // Constructor for injecting dependencies in tests.
   MediaRouterActionController(
       Profile* profile,
       media_router::MediaRouter* router,
       ComponentMigrationHelper::ComponentActionDelegate*
           component_action_delegate,
       ComponentMigrationHelper* component_migration_helper);
   ~MediaRouterActionController() override;
 
+  // Whether the media router action is shown by an administrator policy.
+  static bool IsActionShownByPolicy(content::BrowserContext* context);

[imcheng, 2016/12/15 19:57:38]

might as well use Profile here? Then you can do profile->GetPrefs() in the .cc.

[takumif, 2016/12/15 22:04:14]

Done.

+
   // media_router::IssuesObserver:
   void OnIssueUpdated(const media_router::Issue* issue) override;
 
   // media_router::MediaRoutesObserver:
   void OnRoutesUpdated(const std::vector<media_router::MediaRoute>& routes,
                        const std::vector<media_router::MediaRoute::Id>&
                            joinable_route_ids) override;
 
   // Called when a Media Router dialog is shown or hidden, and updates the
   // visibility of the action icon. Overridden in tests.
@@ skipping 25 matching lines @@
   ComponentMigrationHelper::ComponentActionDelegate* const
       component_action_delegate_;
 
   // Responsible for changing the pref to always show or hide component actions.
   // It is owned by ToolbarActionsModel and outlives |this|.
   ComponentMigrationHelper* const component_migration_helper_;
 
   bool has_issue_ = false;
   bool has_local_display_route_ = false;
 
+  // Whether the media router action is shown by an administrator policy.
+  bool shown_by_policy_;
+
   // The number of dialogs that are currently open.
   size_t dialog_count_ = 0;
 
   PrefChangeRegistrar pref_change_registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterActionController);
 };
 
 #endif  // CHROME_BROWSER_UI_TOOLBAR_MEDIA_ROUTER_ACTION_CONTROLLER_H_