IndexedDB: One transaction coordinator per database

IndexedDB: One transaction coordinator per database
https://bugs.webkit.org/show_bug.cgi?id=97501

Reviewed by Tony Chang.

Source/WebCore:

Per the IDB spec, transactions only need to be sequenced within databases.
The implementation was using one coordinator per factory backend (effectively
a singleton), which would prevent parallel execution of transactions in different
databases. Moved ownership of the transaction coordinator to the database backend.

Tests: storage/indexeddb/transaction-coordination-across-databases.html
       storage/indexeddb/transaction-readwrite-exclusive.html

* Modules/indexeddb/IDBDatabaseBackendImpl.cpp:
(WebCore::IDBDatabaseBackendImpl::create):
(WebCore):
(WebCore::IDBDatabaseBackendImpl::IDBDatabaseBackendImpl):
* Modules/indexeddb/IDBDatabaseBackendImpl.h:
(IDBDatabaseBackendImpl):
* Modules/indexeddb/IDBFactoryBackendImpl.cpp:
(WebCore::IDBFactoryBackendImpl::deleteDatabase):
(WebCore::IDBFactoryBackendImpl::open):
* Modules/indexeddb/IDBFactoryBackendImpl.h:
(WebCore):
(IDBFactoryBackendImpl):
* Modules/indexeddb/IDBTransactionCoordinator.cpp:
(WebCore::IDBTransactionCoordinator::create):
(WebCore::IDBTransactionCoordinator::IDBTransactionCoordinator):
* Modules/indexeddb/IDBTransactionCoordinator.h:
(IDBTransactionCoordinator):

Source/WebKit/chromium:

Remove obsolete argument.

* tests/IDBDatabaseBackendTest.h:

LayoutTests:

Test that transactions can be parallelized across databases, and ensure that
read/write transactions with overlapping scopes are not parallelized within a
database.

* storage/indexeddb/resources/transaction-coordination-across-databases.js: Added.
* storage/indexeddb/resources/transaction-readwrite-exclusive.js: Added.
* storage/indexeddb/transaction-coordination-across-databases-expected.txt: Added.
* storage/indexeddb/transaction-coordination-across-databases.html: Added.
* storage/indexeddb/transaction-readwrite-exclusive-expected.txt: Added.
* storage/indexeddb/transaction-readwrite-exclusive.html: Added.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@129534 268f45cc-cd09-0410-ab3c-d52691b4dbfc