CefRenderHandler::OnPaint stops getting called in 3.3325

[pingu7931]

We're using 3.3325.1758 for the performance reasons specified in https://www.magpcss.org/ceforum/viewtopic.php?f=6&t=15988&p=38435#p38435.

Our product uses CEF in OSR mode. To ensure we have a fully rendered page, including say any post-loaded JavaScript images, we reset a timer every time CefRenderHandler::OnPaint is called to see if there is still any visual activity on the page. This way we can specify a repaint delay and get an impression of the complete page. This has all been working fine for smaller files.

Recently a customer submitted a very large (26MB) HTML file with lots of data tables which, once loaded, runs JavaScript graph generators on those data tables. This JavaScript takes 5 minutes to render all the graphs in Chrome. The OnPaint/repaint delay should enable the engine to wait until all these graphs are painted. The result however is that only a fifth of them are.

When I debug our CEF implementation I found that OnPaint is getting called say 20-30 times and then not at all. If I enforce a wait for the say 6 minutes to all the JavaScript to complete the page renders correctly. Any ideas why this might be? Is there an alternative way to achieve the same result with this version?

[pingu7931]

I have now spent a day updating to CEF 85.2.9 with the same behaviour but now around 44 calls to OnPaint.