30 fps cap

[sunflare]

after testing around a bit it looks like CropScaleReadbackAndCleanMailbox (in render_widget_host_view_osr.cc) takes too long, so the extra frames are dropped.
what i don't understand is why this still happens when the window is small.

how can it be fast enough to copy 30 1080p worth of pixels every second and still take too long when the bitmaps are 100x100 pixels big?

[sunflare]

When I add --disable-gpu-vsync to the parameters, so that chromium renders more than 60 fps, i can actually get 60 in cef.
It looks like cef only ever gets every other frame that chromium renders in offscreen mode. When the scene is so complex that chromium drops below 120 fps, cef drops below 60.

could it be that copying the pixels from the gpu buffer waits for the next frame to be drawn because its a GL call, which causes the frame to be dropped because the last copy operation isn't finished yet?