Add a policy to always show the Cast toolbar icon

chrome/browser/ui/toolbar/media_router_action_controller.cc

 // 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.
 
 #include "chrome/browser/ui/toolbar/media_router_action_controller.h"
 
 #include "chrome/browser/media/router/media_router_factory.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/toolbar/component_toolbar_actions_factory.h"
 #include "chrome/browser/ui/toolbar/toolbar_actions_model.h"
 #include "chrome/common/pref_names.h"
 
 MediaRouterActionController::MediaRouterActionController(Profile* profile)
     : MediaRouterActionController(
           profile,
           media_router::MediaRouterFactory::GetApiForBrowserContext(profile),
           ToolbarActionsModel::Get(profile),
           ToolbarActionsModel::Get(profile)->component_migration_helper()) {
   DCHECK(component_action_delegate_);
   DCHECK(component_migration_helper_);
 }
 
 MediaRouterActionController::~MediaRouterActionController() {
   DCHECK_EQ(dialog_count_, 0u);
 }
 
+// static
+bool MediaRouterActionController::IsActionShownByPolicy(Profile* profile) {
+  CHECK(profile);
+  const PrefService::Preference* pref =
+      profile->GetPrefs()->FindPreference(prefs::kShowCastIconInToolbar);
+  bool show = false;
+  if (pref->IsManaged())

[msw, 2017/01/05 01:14:57]

q: should this check for a non-null pref?

[takumif, 2017/01/06 22:06:57]

The pref gets registered in profile_impl.cc, so it shouldn't be null.

+    pref->GetValue()->GetAsBoolean(&show);
+  return show;
+}
+
 void MediaRouterActionController::OnIssue(const media_router::Issue& issue) {
   has_issue_ = true;
   MaybeAddOrRemoveAction();
 }
 
 void MediaRouterActionController::OnIssuesCleared() {
   has_issue_ = false;
   MaybeAddOrRemoveAction();
 }
 
@@ skipping 24 matching lines @@
 MediaRouterActionController::MediaRouterActionController(
     Profile* profile,
     media_router::MediaRouter* router,
     extensions::ComponentMigrationHelper::ComponentActionDelegate*
         component_action_delegate,
     extensions::ComponentMigrationHelper* component_migration_helper)
     : media_router::IssuesObserver(router),
       media_router::MediaRoutesObserver(router),
       profile_(profile),
       component_action_delegate_(component_action_delegate),
-      component_migration_helper_(component_migration_helper) {
-  DCHECK(profile_);
+      component_migration_helper_(component_migration_helper),
+      shown_by_policy_(
+          MediaRouterActionController::IsActionShownByPolicy(profile)) {
+  CHECK(profile_);
   media_router::IssuesObserver::Init();
   pref_change_registrar_.Init(profile->GetPrefs());
   pref_change_registrar_.Add(
       prefs::kToolbarMigratedComponentActionStatus,
       base::Bind(&MediaRouterActionController::MaybeAddOrRemoveAction,
                  base::Unretained(this)));
 }
 
 void MediaRouterActionController::MaybeAddOrRemoveAction() {
   if (ShouldEnableAction()) {
     if (!component_action_delegate_->HasComponentAction(
             ComponentToolbarActionsFactory::kMediaRouterActionId)) {
       component_action_delegate_->AddComponentAction(
           ComponentToolbarActionsFactory::kMediaRouterActionId);
     }
   } else if (component_action_delegate_->HasComponentAction(
                  ComponentToolbarActionsFactory::kMediaRouterActionId)) {
     component_action_delegate_->RemoveComponentAction(
         ComponentToolbarActionsFactory::kMediaRouterActionId);
   }
 }
 
 bool MediaRouterActionController::ShouldEnableAction() const {
-  return has_local_display_route_ || has_issue_ || dialog_count_ ||
+  return shown_by_policy_ || has_local_display_route_ || has_issue_ ||
+         dialog_count_ ||
          component_migration_helper_->GetComponentActionPref(
              ComponentToolbarActionsFactory::kMediaRouterActionId);
 }