Cherry-pick 6c86b50. rdar://126717672

    [iOS] CRASH: exception thrown from AVVideoCaptureSource::stopSession()
    https://bugs.webkit.org/show_bug.cgi?id=273088
    rdar://126717672

    Reviewed by Eric Carlson.

    Crashtracer data shows that an exception is thrown from -[AVCaptureSession stopRunning] because that
    method is called after -beginConfiguration, but before -commitConfiguration. Make this method robust
    to that exception, and add our own ASSERT that we are not in the middle of configuration in order to
    catch this case before it gets to AVCapture.

    * Source/WebCore/platform/mediastream/mac/AVVideoCaptureSource.mm:
    (WebCore::AVVideoCaptureSource::stopSession):

    Canonical link: https://commits.webkit.org/277869@main

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

@@ -340,7 +340,14 @@ static double cameraZoomScaleFactor(AVCaptureDeviceType deviceType)
 
 void AVVideoCaptureSource::stopSession()
 {
-    [m_session stopRunning];
+    ASSERT(!m_beginConfigurationCount);
+
+    @try {
+        [m_session stopRunning];
+    } @catch(NSException *exception) {
+        ERROR_LOG_IF(loggerPtr(), LOGIDENTIFIER, "error calling -stopRunning ", [[exception name] UTF8String], ", reason : ", exception.reason);
+    }
+
     rejectPendingPhotoRequest("Track stopped"_s);
 }