[iOS] TestWebKitAPI.IndexedDB.IndexedDBSuspendImminently is consistently timing out on release

[szewai]

ecaa543

[iOS] TestWebKitAPI.IndexedDB.IndexedDBSuspendImminently is consistently timing out on release
https://bugs.webkit.org/show_bug.cgi?id=240886

Reviewed by Chris Dumez.

Modify the test to make it less flaky and easier to debug. The changes including:
1. "Continue" message is sent from web page after first operation completes, instead of database is opened, so we can
make sure transaction is started before _sendNetworkProcessWillSuspendImminently.
2. Call _sendNetworkProcessDidResume after first transaction is aborted ("Abort" message is received), so we can make
sure network process has handled suspend message.
3. The test pages create only two different transactions: the first is a long transaction, which keeps running until it
gets aborted by suspension; the second is a short transaction, which is only used to prove that not all transactions
will be aborted by suspension. We used to create 10 identical transactions and it could be any of them gets aborted.

* Tools/TestWebKitAPI/Tests/WebKitCocoa/IndexedDBSuspendImminently.html:
* Tools/TestWebKitAPI/Tests/WebKitCocoa/IndexedDBSuspendImminently.mm:
(TEST):

Canonical link: https://commits.webkit.org/251208@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@295117 268f45cc-cd09-0410-ab3c-d52691b4dbfc

[webkit-early-warning-system]

Committed r295117 (251208@main): https://commits.webkit.org/251208@main

Reviewed commits have been landed. Closing PR #1225 and removing active labels.