Remove explicit usage of SequencedWorkerPool from UploadList.

components/upload_list/upload_list.h

 // Copyright 2013 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 COMPONENTS_UPLOAD_LIST_UPLOAD_LIST_H_
 #define COMPONENTS_UPLOAD_LIST_UPLOAD_LIST_H_
 
 #include <stddef.h>
 
 #include <string>
 #include <vector>
 
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "base/threading/thread_checker.h"
+#include "base/sequence_checker.h"
 #include "base/time/time.h"
 
 namespace base {
 class SequencedTaskRunner;
-class SequencedWorkerPool;
+class TaskRunner;
 }
 
 // Loads and parses an upload list text file of the format
 // upload_time,upload_id[,local_id[,capture_time[,state]]]
 // upload_time,upload_id[,local_id[,capture_time[,state]]]
 // etc.
 // where each line represents an upload. |upload_time| and |capture_time| are in
 // Unix time. |state| is an int in the range of UploadInfo::State. Must be used
 // from the UI thread. The loading and parsing is done on a blocking pool task
 // runner. A line may or may not contain |local_id|, |capture_time|, and
@@ skipping 45 matching lines @@
     // UI thread.
     virtual void OnUploadListAvailable() = 0;
 
    protected:
     virtual ~Delegate() {}
   };
 
   // Creates a new upload list with the given callback delegate.
   UploadList(Delegate* delegate,
              const base::FilePath& upload_log_path,
-             const scoped_refptr<base::SequencedWorkerPool>& worker_pool);
+             scoped_refptr<base::TaskRunner> task_runner);
 
   // Starts loading the upload list. OnUploadListAvailable will be called when
   // loading is complete.
   void LoadUploadListAsynchronously();
 
   // Asynchronously requests a user triggered upload.
   void RequestSingleCrashUploadAsync(const std::string& local_id);
 
   // Clears the delegate, so that any outstanding asynchronous load will not
   // call the delegate on completion.
@@ skipping 13 matching lines @@
   // Requests a user triggered upload for a crash report with a given id.
   virtual void RequestSingleCrashUpload(const std::string& local_id);
 
   const base::FilePath& upload_log_path() const;
 
  private:
   friend class base::RefCountedThreadSafe<UploadList>;
 
   // Manages the background thread work for LoadUploadListAsynchronously().
   void PerformLoadAndNotifyDelegate(
-      const scoped_refptr<base::SequencedTaskRunner>& task_runner);
+      scoped_refptr<base::SequencedTaskRunner> task_runner);
 
   // Calls the delegate's callback method, if there is a delegate. Stores
   // the newly loaded |uploads| into |uploads_| on the delegate's task runner.
   void SetUploadsAndNotifyDelegate(std::vector<UploadInfo> uploads);
 
   // Parses upload log lines, converting them to UploadInfo entries.
   void ParseLogEntries(const std::vector<std::string>& log_entries,
                        std::vector<UploadInfo>* uploads);
 
-  // |thread_checker_| ensures that |uploads_| is only set from the task runner
-  // that created the UploadList.
-  base::ThreadChecker thread_checker_;
+  // Ensures that this class' thread unsafe state is only accessed from the
+  // sequence that owns this UploadList.
+  base::SequenceChecker sequence_checker_;
+
   std::vector<UploadInfo> uploads_;
+
   Delegate* delegate_;
 
   const base::FilePath upload_log_path_;
 
-  scoped_refptr<base::SequencedWorkerPool> worker_pool_;
+  const scoped_refptr<base::TaskRunner> task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(UploadList);
 };
 
 #endif  // COMPONENTS_UPLOAD_LIST_UPLOAD_LIST_H_