components/scheduler/test/lazy_scheduler_message_loop_delegate_for_tests.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_SCHEDULER_TEST_LAZY_SCHEDULER_MESSAGE_LOOP_DELEGATE_FOR_TESTS_H_
   6 #define COMPONENTS_SCHEDULER_TEST_LAZY_SCHEDULER_MESSAGE_LOOP_DELEGATE_FOR_TESTS_H_
   7
   8 #include "base/message_loop/message_loop.h"
   9 #include "components/scheduler/child/scheduler_task_runner_delegate.h"
  10
  11 namespace scheduler {
  12
  13 // This class connects the scheduler to a MessageLoop, but unlike
  14 // SchedulerMessageLoopDelegate it allows the message loop to be created lazily
  15 // after the scheduler has been brought up. This is needed in testing scenarios
  16 // where Blink is initialized before a MessageLoop has been created.
  17 //
  18 // TODO(skyostil): Fix the relevant test suites and remove this class
  19 // (crbug.com/495659).
  20 class LazySchedulerMessageLoopDelegateForTests
  21     : public SchedulerTaskRunnerDelegate {
  22  public:
  23   static scoped_refptr<LazySchedulerMessageLoopDelegateForTests> Create();
  24
  25   // SchedulerTaskRunnerDelegate implementation
  26   void SetDefaultTaskRunner(
  27       scoped_refptr<base::SingleThreadTaskRunner> task_runner) override;
  28   void RestoreDefaultTaskRunner() override;
  29   bool PostDelayedTask(const tracked_objects::Location& from_here,
  30                        const base::Closure& task,
  31                        base::TimeDelta delay) override;
  32   bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
  33                                   const base::Closure& task,
  34                                   base::TimeDelta delay) override;
  35   bool RunsTasksOnCurrentThread() const override;
  36   bool IsNested() const override;
  37
  38  private:
  39   LazySchedulerMessageLoopDelegateForTests();
  40   ~LazySchedulerMessageLoopDelegateForTests() override;
  41
  42   bool HasMessageLoop() const;
  43   base::MessageLoop* EnsureMessageLoop() const;
  44
  45   mutable base::MessageLoop* message_loop_;
  46   base::PlatformThreadId thread_id_;
  47
  48   // A task runner which hasn't yet been overridden in the message loop.
  49   mutable scoped_refptr<base::SingleThreadTaskRunner> pending_task_runner_;
  50   mutable scoped_refptr<base::SingleThreadTaskRunner> original_task_runner_;
  51
  52   DISALLOW_COPY_AND_ASSIGN(LazySchedulerMessageLoopDelegateForTests);
  53 };
  54
  55 }  // namespace scheduler
  56
  57 #endif  // COMPONENTS_SCHEDULER_TEST_LAZY_SCHEDULER_MESSAGE_LOOP_DELEGATE_FOR_TESTS_H_