content: Cleanup class/struct forward declarations

content/browser/indexed_db/indexed_db_database.h

 // Copyright (c) 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 CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DATABASE_H_
 #define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DATABASE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 16 matching lines @@
 #include "content/browser/indexed_db/list_set.h"
 #include "content/common/indexed_db/indexed_db_metadata.h"
 #include "third_party/WebKit/public/platform/modules/indexeddb/WebIDBTypes.h"
 
 namespace url {
 class Origin;
 }
 
 namespace content {
 
-class IndexedDBBlobInfo;
 class IndexedDBConnection;
 class IndexedDBDatabaseCallbacks;
 class IndexedDBFactory;
 class IndexedDBKey;
 class IndexedDBKeyPath;
 class IndexedDBKeyRange;
-class IndexedDBObservation;
 class IndexedDBObserverChanges;
 class IndexedDBTransaction;
 struct IndexedDBValue;
 
 class CONTENT_EXPORT IndexedDBDatabase
     : NON_EXPORTED_BASE(public base::RefCounted<IndexedDBDatabase>) {
  public:
   // An index and corresponding set of keys
   using IndexKeys = std::pair<int64_t, std::vector<IndexedDBKey>>;
 
@@ skipping 296 matching lines @@
   // is executing. It prevents rentrant calls if the active request completes
   // synchronously.
   bool processing_pending_requests_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(IndexedDBDatabase);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_DATABASE_H_