[site-isolation] http/tests/webrtc/audioSessionInFrames.html is a permanent failure
https://bugs.webkit.org/show_bug.cgi?id=321166
rdar://184204754

Reviewed by Eric Carlson.

This test exposed four separate issues.

1) navigator.audioSession.type read "auto" in a cross-site iframe: a WebContent process
    joining an existing page never received the top document's DocumentSyncData. The
    broadcast on change only reached processes that already hosted the page, and
    RemotePageParameters carried the main document URL but no sync data, so the iframe's
    Page kept a default-constructed DocumentSyncData. 100% failure whenever the iframe was
    site-isolated into its own process.

2) navigator.audioSession.state read "inactive" there: the DOM audio session state was not
    page-scoped, so a passive iframe process consulted its own RemoteAudioSession, which
    never activated. RemoteAudioSessionConfiguration::isActive was that process's own
    activation request, and the GPU process only pushed ConfigurationChanged for mute,
    buffer size and sample rate. Also 100% failure once 1) was fixed.

3) getUserMedia resolved once the audio session category had been applied but before the
    activation completed, so JS reading state right after the await could see "inactive" in
    any configuration. 45% failure without site isolation.

4) The test only started listening for the frame's message after waiting for the frame to load.
    With the frame in another process, the message and the load notification travelled as separate
    IPCs, so a message that arrived first was dropped and the test waited forever. 8% of runs,
    reported as a timeout.

DocumentSyncData is now sent in the remote page creation parameters and adopted by pages
that do not host the local main frame, and the audio session state joins it as a
synchronized, page-scoped value that remote-frame processes read and dispatch statechange
from. For 3), audioCaptureSourceStateChanged() returns GenericPromise::all() of the
category and the activation, so waiters (the getUserMedia promise, the track mute/unmute
events) see a session that is both categorised and active; activation is still requested
synchronously, so callers that do not wait keep observing AudioSession::isActive()
immediately, as 318537@main requires.
The test now starts listening for the message before it creates the frame.

* LayoutTests/http/tests/webrtc/audioSessionInFrames.html: Listen for the frame's message
before creating the frame.
* LayoutTests/platform/ios-site-isolation/TestExpectations: Unskip the now-passing test.
* LayoutTests/platform/mac-site-isolation/TestExpectations: Ditto.
* Source/WebCore/Modules/audiosession/DOMAudioSession.cpp:
(WebCore::DOMAudioSession::state const): Use the effective state.
(WebCore::DOMAudioSession::currentState const): Read the synchronized state when the page
has no local main frame, otherwise compute it and publish it from the top document.
(WebCore::DOMAudioSession::topDocumentAudioSessionStateChanged): Schedule a statechange
event for a state computed in another process.
(WebCore::DOMAudioSession::scheduleStateChangeEvent): Capture the effective state.
* Source/WebCore/Modules/audiosession/DOMAudioSession.h:
* Source/WebCore/Modules/audiosession/NavigatorAudioSession.cpp:
(WebCore::NavigatorAudioSession::audioSessionIfExists): Added; does not provision the
supplement.
* Source/WebCore/Modules/audiosession/NavigatorAudioSession.h:
* Source/WebCore/dom/Document.cpp:
(WebCore::Document::populateDocumentSyncDataForNewlyConstructedDocument): Handle the new
data type.
* Source/WebCore/page/DocumentSyncData.in: Add AudioSessionState.
* Source/WebCore/page/Page.cpp:
(WebCore::Page::setAudioSessionState): Store and broadcast the page's audio session state.
(WebCore::Page::audioSessionState const):
(WebCore::Page::updateTopDocumentSyncData): Notify existing DOMAudioSession objects when
the synchronized state changes.
* Source/WebCore/page/Page.h:
* Source/WebCore/platform/audio/MediaSessionManagerInterface.cpp:
(WebCore::MediaSessionManagerInterface::audioCaptureSourceStateChanged): Return a promise
covering both the category and the activation; keep requesting activation synchronously.
* Source/WebKit/Shared/WebCoreArgumentCodersMedia.serialization.in: Declare
DOMAudioSessionState for IPC.
* Source/WebKit/Shared/WebPageCreationParameters.h:
* Source/WebKit/Shared/WebPageCreationParameters.serialization.in: Carry the top document's
DocumentSyncData in RemotePageParameters.
* Source/WebKit/UIProcess/ProvisionalPageProxy.cpp:
(WebKit::ProvisionalPageProxy::initializeWebPage): Send fresh sync data; the provisional
page commits a new top document.
* Source/WebKit/UIProcess/RemotePageProxy.cpp:
(WebKit::RemotePageProxy::injectPageIntoNewProcess): Send the current sync data.
(WebKit::RemotePageProxy::setDrawingArea): Ditto.
* Source/WebKit/UIProcess/WebPageProxy.cpp:
(WebKit::WebPageProxy::topDocumentSyncData const): Added.
* Source/WebKit/UIProcess/WebPageProxy.h:
* Source/WebKit/WebProcess/WebPage/WebPage.cpp:
(WebKit::m_allowsImmersiveEnvironments):
* Tools/TestWebKitAPI/Resources/getUserMedia.html: Wait for the getUserMedia promise to resolved before calling stop().
* Tools/TestWebKitAPI/SourcesCocoa.txt: Added missing file so API test gets compiled.

Canonical link: https://commits.webkit.org/318776@main