Move basic IDBBackingStoreTransaction operations to IDBServerConnection
https://bugs.webkit.org/show_bug.cgi?id=124244

Reviewed by Tim Horton (and unofficially Anders Carlsson).

This patch:
- Makes IDBBackingStore the owner of an IDBBackingStoreTransaction.
- Adds the integer transaction ID to IDBBackingStoreTransaction for reference.
- Removes IDBTransactionBackend’s reliance on IDBBackingStoreTransaction by moving
  necessary methods to IDBServerConnection.
- Renames the IDBTransactionBackend::backingStoreTransaction() accessor to
  deprecatedBackingStoreTransaction to make it clear it’s on the way out.

* Modules/indexeddb/IDBBackingStoreInterface.h:

* Modules/indexeddb/IDBDatabaseBackend.cpp:
(WebCore::IDBDatabaseBackend::setIndexKeys):

* Modules/indexeddb/IDBServerConnection.h:

* Modules/indexeddb/IDBTransactionBackend.cpp:
(WebCore::IDBTransactionBackend::IDBTransactionBackend):
(WebCore::IDBTransactionBackend::~IDBTransactionBackend):
(WebCore::IDBTransactionBackend::deprecatedBackingStoreTransaction):
(WebCore::IDBTransactionBackend::scheduleTask):
(WebCore::IDBTransactionBackend::abort):
(WebCore::IDBTransactionBackend::commit):
(WebCore::IDBTransactionBackend::taskTimerFired):
* Modules/indexeddb/IDBTransactionBackend.h:

* Modules/indexeddb/IDBTransactionBackendOperations.cpp:
(WebCore::CreateObjectStoreOperation::perform):
(WebCore::CreateIndexOperation::perform):
(WebCore::DeleteIndexOperation::perform):
(WebCore::GetOperation::perform):
(WebCore::PutOperation::perform):
(WebCore::OpenCursorOperation::perform):
(WebCore::CountOperation::perform):
(WebCore::DeleteRangeOperation::perform):
(WebCore::ClearOperation::perform):
(WebCore::DeleteObjectStoreOperation::perform):
(WebCore::IDBDatabaseBackend::VersionChangeOperation::perform):

* Modules/indexeddb/leveldb/IDBBackingStoreLevelDB.cpp:
(WebCore::IDBBackingStoreLevelDB::makeIndexWriters):
(WebCore::IDBBackingStoreLevelDB::generateKey):
(WebCore::IDBBackingStoreLevelDB::updateKeyGenerator):
(WebCore::IDBBackingStoreLevelDB::establishBackingStoreTransaction):
(WebCore::IDBBackingStoreLevelDB::deprecatedBackingStoreTransaction):
(WebCore::IDBBackingStoreLevelDB::removeBackingStoreTransaction):
* Modules/indexeddb/leveldb/IDBBackingStoreLevelDB.h:

* Modules/indexeddb/leveldb/IDBBackingStoreTransactionLevelDB.cpp:
(WebCore::IDBBackingStoreTransactionLevelDB::IDBBackingStoreTransactionLevelDB):
(WebCore::IDBBackingStoreTransactionLevelDB::~IDBBackingStoreTransactionLevelDB):
(WebCore::IDBBackingStoreTransactionLevelDB::resetTransaction):
* Modules/indexeddb/leveldb/IDBBackingStoreTransactionLevelDB.h:

* Modules/indexeddb/leveldb/IDBServerConnectionLevelDB.cpp:
(WebCore::IDBServerConnectionLevelDB::IDBServerConnectionLevelDB):
(WebCore::IDBServerConnectionLevelDB::deprecatedBackingStoreTransaction):
(WebCore::IDBServerConnectionLevelDB::openTransaction):
(WebCore::IDBServerConnectionLevelDB::beginTransaction):
(WebCore::IDBServerConnectionLevelDB::commitTransaction):
(WebCore::IDBServerConnectionLevelDB::resetTransaction):
(WebCore::IDBServerConnectionLevelDB::rollbackTransaction):
* Modules/indexeddb/leveldb/IDBServerConnectionLevelDB.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@159177 268f45cc-cd09-0410-ab3c-d52691b4dbfc