Pass Callback to TaskRunner by value and consume it on invocation (1)

chrome/browser/chromeos/login/users/fake_chrome_user_manager.cc

 // Copyright 2015 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/chromeos/login/users/fake_chrome_user_manager.h"
 
 #include <set>
 
+#include "base/callback.h"
+#include "base/callback_helpers.h"
 #include "base/command_line.h"
 #include "base/memory/ptr_util.h"
 #include "base/sys_info.h"
 #include "chrome/browser/chromeos/login/users/chrome_user_manager.h"
 #include "chrome/browser/chromeos/login/users/chrome_user_manager_util.h"
 #include "chrome/browser/chromeos/login/users/fake_supervised_user_manager.h"
 #include "chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager.h"
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "chrome/grit/theme_resources.h"
@@ skipping 10 matching lines @@
 class FakeTaskRunner : public base::TaskRunner {
  public:
   FakeTaskRunner() = default;
 
  protected:
   ~FakeTaskRunner() override {}
 
  private:
   // base::TaskRunner overrides.
   bool PostDelayedTask(const tracked_objects::Location& from_here,
-                       const base::Closure& task,
+                       base::Closure task,
                        base::TimeDelta delay) override {
-    task.Run();
+    std::move(task).Run();

[sky, 2017/03/22 17:34:11]

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     return true;
   }
   bool RunsTasksOnCurrentThread() const override { return true; }
 
   DISALLOW_COPY_AND_ASSIGN(FakeTaskRunner);
 };
 
 }  // namespace
 
 namespace chromeos {
@@ skipping 578 matching lines @@
   if (active_account_id_.is_valid()) {
     for (auto* user : users_) {
       if (user->GetAccountId() == active_account_id_)
         return user;
     }
   }
   return users_[0];
 }
 
 }  // namespace chromeos