Make base::Timer sequence-friendly.

content/browser/loader/upload_progress_tracker.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 CONTENT_BROWSER_LOADER_UPLOAD_PROGRESS_TRACKER_H_
 #define CONTENT_BROWSER_LOADER_UPLOAD_PROGRESS_TRACKER_H_
 
 #include <stdint.h>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "base/single_thread_task_runner.h"
-#include "base/threading/thread_task_runner_handle.h"
+#include "base/sequenced_task_runner.h"
+#include "base/threading/sequenced_task_runner_handle.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "content/common/content_export.h"
 #include "net/base/upload_progress.h"
 
-namespace base {
-class SingleThreadTaskRunner;
-}
-
 namespace tracked_objects {
 class Location;
 }
 
 namespace net {
 class URLRequest;
 }
 
 namespace content {
 
 // UploadProgressTracker watches the upload progress of a URL loading, and sends
 // the progress to the client in a suitable granularity and frequency.
 class CONTENT_EXPORT UploadProgressTracker {
  public:
   using UploadProgressReportCallback =
       base::RepeatingCallback<void(const net::UploadProgress&)>;
 
   UploadProgressTracker(const tracked_objects::Location& location,
                         UploadProgressReportCallback report_progress,
                         net::URLRequest* request,
-                        scoped_refptr<base::SingleThreadTaskRunner>
-                            task_runner = base::ThreadTaskRunnerHandle::Get());
+                        scoped_refptr<base::SequencedTaskRunner> task_runner =
+                            base::SequencedTaskRunnerHandle::Get());
   ~UploadProgressTracker();
 
   void OnAckReceived();
   void OnUploadCompleted();
 
+  static base::TimeDelta GetUploadProgressIntervalForTesting();
+
  private:
   // Overridden by tests to use a fake time and progress.
   virtual base::TimeTicks GetCurrentTime() const;
   virtual net::UploadProgress GetUploadProgress() const;
 
   void ReportUploadProgressIfNeeded();
 
   net::URLRequest* request_;  // Not owned.
 
   uint64_t last_upload_position_ = 0;
   bool waiting_for_upload_progress_ack_ = false;
   base::TimeTicks last_upload_ticks_;
   base::RepeatingTimer progress_timer_;
 
   UploadProgressReportCallback report_progress_;
 
   DISALLOW_COPY_AND_ASSIGN(UploadProgressTracker);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_UPLOAD_PROGRESS_TRACKER_H_