Move Indexed DB from dedicated thread to task scheduler

content/browser/indexed_db/indexed_db_callbacks.h

 // Copyright (c) 2012 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_INDEXED_DB_INDEXED_DB_CALLBACKS_H_
 #define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_CALLBACKS_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "base/sequence_checker.h"
 #include "base/strings/string16.h"
-#include "base/threading/thread_checker.h"
 #include "content/browser/indexed_db/indexed_db_database_error.h"
 #include "content/browser/indexed_db/indexed_db_dispatcher_host.h"
 #include "content/common/indexed_db/indexed_db.mojom.h"
 #include "content/common/indexed_db/indexed_db_key.h"
 #include "content/common/indexed_db/indexed_db_key_path.h"
 #include "url/origin.h"
 
 namespace base {
 class SequencedTaskRunner;
 }
 
 namespace content {
 class IndexedDBConnection;
 class IndexedDBCursor;
 class IndexedDBDatabase;
 struct IndexedDBDataLossInfo;
 struct IndexedDBDatabaseMetadata;
 struct IndexedDBReturnValue;
 struct IndexedDBValue;
 
-// Expected to be constructed on IO thread and called/deleted from IDB thread.
+// Expected to be constructed on IO thread and called/deleted from IDB sequence.
 class CONTENT_EXPORT IndexedDBCallbacks
     : public base::RefCounted<IndexedDBCallbacks> {
  public:
   // Destructively converts an IndexedDBValue to a Mojo Value.
   static ::indexed_db::mojom::ValuePtr ConvertAndEraseValue(
       IndexedDBValue* value);
 
   IndexedDBCallbacks(
       base::WeakPtr<IndexedDBDispatcherHost> dispatcher_host,
       const url::Origin& origin,
@@ skipping 71 matching lines @@
   bool connection_created_ = false;
 
   // Used to assert that OnSuccess is only called if there was no data loss.
   blink::WebIDBDataLoss data_loss_;
 
   // The "blocked" event should be sent at most once per request.
   bool sent_blocked_ = false;
   base::TimeTicks connection_open_start_time_;
 
   std::unique_ptr<IOThreadHelper, BrowserThread::DeleteOnIOThread> io_helper_;
-  base::ThreadChecker thread_checker_;
+  SEQUENCE_CHECKER(sequence_checker_);
 
   DISALLOW_COPY_AND_ASSIGN(IndexedDBCallbacks);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_CALLBACKS_H_