[macOS] Reject getDisplayMedia prompt if system picker times out

https://bugs.webkit.org/show_bug.cgi?id=243679
<rdar://98194903>

Reviewed by Jer Noble.

Set a 60 second timeout when invoking the ScreenCaptureKit system picker, fail capture if
if it fires.

* Source/WebCore/platform/mediastream/mac/ScreenCaptureKitSharingSessionManager.h:
* Source/WebCore/platform/mediastream/mac/ScreenCaptureKitSharingSessionManager.mm:
(WebCore::ScreenCaptureKitSharingSessionManager::pickerCanceledForSession): Clear the
timer. Drive-by: remove the session from the pending list.
(WebCore::ScreenCaptureKitSharingSessionManager::sessionDidEnd): Add logging.
(WebCore::ScreenCaptureKitSharingSessionManager::sessionDidChangeContent): Clear the
timer. Add logging.
(WebCore::ScreenCaptureKitSharingSessionManager::promptForGetDisplayMedia): Set timer,
cancel session if it fires.
(WebCore::ScreenCaptureKitSharingSessionManager::takeSharingSessionForFilter): Add logging.

Canonical link: https://commits.webkit.org/253260@main

Source/WebCore/platform/mediastream/mac/ScreenCaptureKitSharingSessionManager.h

@@ -66,6 +66,7 @@ class ScreenCaptureKitSharingSessionManager : public CanMakeWeakPtr<ScreenCaptur
     Vector<RetainPtr<SCContentSharingSession>> m_pendingCaptureSessions;
     RetainPtr<WebDisplayMediaPromptHelper> m_promptHelper;
     CompletionHandler<void(std::optional<CaptureDevice>)> m_completionHandler;
+    std::unique_ptr<RunLoop::Timer<ScreenCaptureKitSharingSessionManager>> m_promptWatchdogTimer;
 };
 
 } // namespace WebCore

Source/WebCore/platform/mediastream/mac/ScreenCaptureKitSharingSessionManager.mm

@@ -165,9 +165,18 @@ static bool screenCaptureKitPickerFeatureEnabled()
     ASSERT(isMainThread());
     ASSERT(m_completionHandler);
 
+    RELEASE_LOG(WebRTC, "ScreenCaptureKitSharingSessionManager::pickerCanceledForSession");
+
+    m_promptWatchdogTimer = nullptr;
     if (!m_completionHandler)
         return;
 
+    auto index = m_pendingCaptureSessions.findIf([session](auto pendingSession) {
+        return [pendingSession isEqual:session.get()];
+    });
+    if (index != notFound)
+        m_pendingCaptureSessions.remove(index);
+
     [m_promptHelper stopObservingSession:session.get()];
     [session end];
 
@@ -179,6 +188,8 @@ static bool screenCaptureKitPickerFeatureEnabled()
 {
     ASSERT(isMainThread());
 
+    RELEASE_LOG(WebRTC, "ScreenCaptureKitSharingSessionManager::sessionDidEnd");
+
     [m_promptHelper stopObservingSession:session.get()];
 
     auto index = m_pendingCaptureSessions.findIf([session](auto pendingSession) {
@@ -194,11 +205,15 @@ static bool screenCaptureKitPickerFeatureEnabled()
 {
     ASSERT(isMainThread());
 
+    m_promptWatchdogTimer = nullptr;
+
     if ([session content].type == SCContentFilterTypeNothing) {
         sessionDidEnd(session);
         return;
     }
 
+    RELEASE_LOG(WebRTC, "ScreenCaptureKitSharingSessionManager::sessionDidChangeContent");
+
     auto index = m_pendingCaptureSessions.findIf([session](auto pendingSession) {
         return [pendingSession isEqual:session.get()];
     });
@@ -246,6 +261,8 @@ static bool screenCaptureKitPickerFeatureEnabled()
     ASSERT(isAvailable());
     ASSERT(!m_completionHandler);
 
+    RELEASE_LOG(WebRTC, "ScreenCaptureKitSharingSessionManager::promptForGetDisplayMedia - %s", promptType == PromptType::Window ? "Window" : "Screen");
+
     if (!isAvailable()) {
         completionHandler(std::nullopt);
         return;
@@ -266,12 +283,24 @@ static bool screenCaptureKitPickerFeatureEnabled()
     m_completionHandler = WTFMove(completionHandler);
 
     [session showPickerForType:promptType == PromptType::Window ? SCContentFilterTypeDesktopIndependentWindow : SCContentFilterTypeDisplay];
+
+    constexpr Seconds userPromptWatchdogInterval = 60_s;
+    m_promptWatchdogTimer = makeUnique<RunLoop::Timer<ScreenCaptureKitSharingSessionManager>>(RunLoop::main(), [this, weakThis = WeakPtr { *this }, session = RetainPtr { session }, interval = userPromptWatchdogInterval]() mutable {
+        if (!weakThis)
+            return;
+
+        RELEASE_LOG_ERROR(WebRTC, "ScreenCaptureKitSharingSessionManager::promptForGetDisplayMedia nothing picked after %f seconds, cancelling.", interval.value());
+        pickerCanceledForSession(session);
+    });
+    m_promptWatchdogTimer->startOneShot(userPromptWatchdogInterval);
 }
 
 RetainPtr<SCContentSharingSession> ScreenCaptureKitSharingSessionManager::takeSharingSessionForFilter(SCContentFilter* filter)
 {
     ASSERT(isMainThread());
 
+    RELEASE_LOG(WebRTC, "ScreenCaptureKitSharingSessionManager::takeSharingSessionForFilter");
+
     auto index = m_pendingCaptureSessions.findIf([filter](auto pendingSession) {
         return [filter isEqual:[pendingSession content]];
     });