Merge IDBTransactionBackendInterface and IDBTransactionBackendImpl

Merge IDBTransactionBackendInterface and IDBTransactionBackendImpl
https://bugs.webkit.org/show_bug.cgi?id=124077

Reviewed by Alexey Proskuryakov.

Source/WebCore:

The abstraction is no longer needed.

* CMakeLists.txt:
* GNUmakefile.list.am:
* WebCore.xcodeproj/project.pbxproj:

* Modules/indexeddb/IDBTransactionBackendInterface.h: Removed.

* Modules/indexeddb/IDBTransactionBackend.cpp: Renamed from Source/WebCore/Modules/indexeddb/IDBTransactionBackendImpl.cpp.
* Modules/indexeddb/IDBTransactionBackend.h: Renamed from Source/WebCore/Modules/indexeddb/IDBTransactionBackendImpl.h.

* Modules/indexeddb/IDBBackingStoreInterface.h:
* Modules/indexeddb/IDBCursorBackend.cpp:
* Modules/indexeddb/IDBCursorBackend.h:
* Modules/indexeddb/IDBDatabaseBackendImpl.cpp:
* Modules/indexeddb/IDBDatabaseBackendImpl.h:
* Modules/indexeddb/IDBFactoryBackendInterface.h:
* Modules/indexeddb/IDBTransactionBackendOperations.h:
* Modules/indexeddb/IDBTransactionCoordinator.cpp:
* Modules/indexeddb/IDBTransactionCoordinator.h:
* Modules/indexeddb/leveldb/IDBBackingStoreLevelDB.cpp:
* Modules/indexeddb/leveldb/IDBBackingStoreLevelDB.h:
* Modules/indexeddb/leveldb/IDBFactoryBackendLevelDB.cpp:
* Modules/indexeddb/leveldb/IDBFactoryBackendLevelDB.h:

Source/WebKit2:

* WebProcess/Databases/IndexedDB/WebIDBFactoryBackend.cpp:
* WebProcess/Databases/IndexedDB/WebIDBFactoryBackend.h:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@158969 268f45cc-cd09-0410-ab3c-d52691b4dbfc