I tried changing CefSettings.animation_frame_rate and the browser lags, everything loads slow, scrolling is slow, it doesn't matter whether I set animation_frame_rate to 30, 60 or 90, it's still the same, it works fine only when I set it to 0, which is strange because the documentation says that when I set it to 0 then the default of 30fps will be used, but when I set it to 30 then it lags. The CPU is fine, only 3-4% in use.
I'm using off-screen rendering in a Panda3D game engine:
http://code.google.com/p/cefpython/wiki/Panda3D
The application is using CefDoMessageLoopWork().
From the documenation:
animation_frame_rate - The number of frames per second (fps) for animation and windowless rendering. When window rendering is enabled and the JavaScript requestAnimationFrame method is used the browser client area will be invalidated at the rate specified. When window rendering is disabled the CefRenderHandler::OnPaint() method will be called at the rate specified. This value must be between 0 and 90. Specify a value of zero for the default frame rate of 30 fps. Changing this value may affect display performance and/or CPU usage.
Using CEF 1, rev 942, branch 1271, Chrome 23.0.1271.95.
It was a bug, the int value was casted to bool, so it was always 1 fps after setting it != 0. Now it works much better after setting it to 60. Thank you.