[IndexedDB] Refactoring to remove ref ptrs and host transaction ids.

content/browser/indexed_db/cursor_impl.cc

 // 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.
 
 #include "content/browser/indexed_db/cursor_impl.h"
 
 #include "content/browser/indexed_db/indexed_db_callbacks.h"
 #include "content/browser/indexed_db/indexed_db_cursor.h"
 #include "content/browser/indexed_db/indexed_db_dispatcher_host.h"
 
 namespace content {
 
 class CursorImpl::IDBThreadHelper {
  public:
-  explicit IDBThreadHelper(scoped_refptr<IndexedDBCursor> cursor);
+  explicit IDBThreadHelper(std::unique_ptr<IndexedDBCursor> cursor);
   ~IDBThreadHelper();
 
   void Advance(uint32_t count, scoped_refptr<IndexedDBCallbacks> callbacks);
   void Continue(const IndexedDBKey& key,
                 const IndexedDBKey& primary_key,
                 scoped_refptr<IndexedDBCallbacks> callbacks);
   void Prefetch(int32_t count, scoped_refptr<IndexedDBCallbacks> callbacks);
   void PrefetchReset(int32_t used_prefetches, int32_t unused_prefetches);
 
  private:
   scoped_refptr<IndexedDBDispatcherHost> dispatcher_host_;
-  scoped_refptr<IndexedDBCursor> cursor_;
+  std::unique_ptr<IndexedDBCursor> cursor_;
   const url::Origin origin_;
 
   DISALLOW_COPY_AND_ASSIGN(IDBThreadHelper);
 };
 
-CursorImpl::CursorImpl(scoped_refptr<IndexedDBCursor> cursor,
+CursorImpl::CursorImpl(std::unique_ptr<IndexedDBCursor> cursor,
                        const url::Origin& origin,
                        scoped_refptr<IndexedDBDispatcherHost> dispatcher_host)
     : helper_(new IDBThreadHelper(std::move(cursor))),
       dispatcher_host_(std::move(dispatcher_host)),
       origin_(origin),
       idb_runner_(base::ThreadTaskRunnerHandle::Get()) {}
 
 CursorImpl::~CursorImpl() {
   idb_runner_->DeleteSoon(FROM_HERE, helper_);
 }
@@ skipping 37 matching lines @@
   for (const auto& uuid : unused_blob_uuids)
     dispatcher_host_->DropBlobData(uuid);
 
   idb_runner_->PostTask(
       FROM_HERE,
       base::Bind(&IDBThreadHelper::PrefetchReset, base::Unretained(helper_),
                  used_prefetches, unused_prefetches));
 }
 
 CursorImpl::IDBThreadHelper::IDBThreadHelper(
-    scoped_refptr<IndexedDBCursor> cursor)
+    std::unique_ptr<IndexedDBCursor> cursor)
     : cursor_(std::move(cursor)) {}
 
-CursorImpl::IDBThreadHelper::~IDBThreadHelper() {}
+CursorImpl::IDBThreadHelper::~IDBThreadHelper() {
+  cursor_->RemoveCursorFromTransaction();
+}
 
 void CursorImpl::IDBThreadHelper::Advance(
     uint32_t count,
     scoped_refptr<IndexedDBCallbacks> callbacks) {
   cursor_->Advance(count, std::move(callbacks));
 }
 
 void CursorImpl::IDBThreadHelper::Continue(
     const IndexedDBKey& key,
     const IndexedDBKey& primary_key,
@@ skipping 14 matching lines @@
 void CursorImpl::IDBThreadHelper::PrefetchReset(int32_t used_prefetches,
                                                 int32_t unused_prefetches) {
   leveldb::Status s =
       cursor_->PrefetchReset(used_prefetches, unused_prefetches);
   // TODO(cmumford): Handle this error (crbug.com/363397)
   if (!s.ok())
     DLOG(ERROR) << "Unable to reset prefetch";
 }
 
 }  // namespace content