Because you have enabled the FPS display.
You can turn it off by pressing the Overlay Hotkey (the second tab of FRAPS).
francesco73 answered on October 3rd 19 at 03:05
Probably because in the settings of chrome you have is the GPU acceleration of the render, and Fraps takes it for the game?
Jaclyn_Ro answered on October 3rd 19 at 03:07
Because FRAPS'do not care which application owns the window, if the active window for OpenGL or DirectX, then it will push back your overlay with fps. And Google Chrome uses OpenGL for rendering graphics.