Why does Chrome prevent my Mac from sleeping? I don't mean browsing the Internet is preventing us from sleeping, that's obvious. I've disabled Safe Sleep to reduce sleep times from 20 seconds to 2, but Chrome doesn't want to play nicely.

Here's the log with Chrome:

15/07/12 1:19:07.975 PM LogMeInGUI[350]: String:WEBSVC|OFFLINE
15/07/12 1:19:13.992 PM WindowServer[75]: Created shield window 0x478 for display 0x04272e80
15/07/12 1:19:13.993 PM WindowServer[75]: device_generate_desktop_screenshot: authw 0x0(0), shield 0x0(0)
15/07/12 1:19:13.000 PM kernel[0]: PM notification timeout (pid 3469, Google Chrome He)
15/07/12 1:19:13.000 PM kernel[0]: PM notification timeout (pid 3474, Google Chrome He)
15/07/12 1:19:14.025 PM WindowServer[75]: device_generate_lock_screen_screenshot: authw 0x0(0), shield 0x0(0)
15/07/12 1:19:14.000 PM kernel[0]: AirPort_Brcm43xx::powerChange: System Sleep 
15/07/12 1:19:20.346 PM WindowServer[75]: handle_will_sleep_auth_and_shield_windows: no action for lock state 1
15/07/12 1:19:20.000 PM kernel[0]: Wake reason: EC LID0
15/07/12 1:19:20.000 PM kernel[0]: AirPort_Brcm43xx::powerChange: System Wake - Full Wake/ Dark Wake / Maintenance wake
15/07/12 1:19:20.000 PM kernel[0]: AirPort_Brcm43xx::checkInterfacePowerState: Check _pwrOffThreadCall!
15/07/12 1:19:20.000 PM kernel[0]: HID tickle 1 ms
15/07/12 1:19:20.000 PM kernel[0]: Previous Sleep Cause: 5


And without:

15/07/12 1:20:39.514 PM WindowServer[75]: Created shield window 0x48d for display 0x04272e80
15/07/12 1:20:39.514 PM WindowServer[75]: device_generate_desktop_screenshot: authw 0x0(0), shield 0x0(0)
15/07/12 1:20:39.545 PM WindowServer[75]: device_generate_lock_screen_screenshot: authw 0x0(0), shield 0x0(0)
15/07/12 1:20:40.000 PM kernel[0]: AirPort_Brcm43xx::powerChange: System Sleep 
15/07/12 1:20:47.351 PM WindowServer[75]: handle_will_sleep_auth_and_shield_windows: no action for lock state 1
15/07/12 1:20:47.000 PM kernel[0]: Wake reason: EC LID0
15/07/12 1:20:47.000 PM kernel[0]: AirPort_Brcm43xx::powerChange: System Wake - Full Wake/ Dark Wake / Maintenance wake
15/07/12 1:20:47.000 PM kernel[0]: AirPort_Brcm43xx::checkInterfacePowerState: Check _pwrOffThreadCall!
15/07/12 1:20:47.000 PM kernel[0]: HID tickle 1 ms
15/07/12 1:20:47.000 PM kernel[0]: Previous Sleep Cause: 5


These lines from the Google Chrome Helper are the reason:

15/07/12 1:19:13.000 PM kernel[0]: PM notification timeout (pid 3469, Google Chrome He)
15/07/12 1:19:13.000 PM kernel[0]: PM notification timeout (pid 3474, Google Chrome He)


What does that mean?

This is a relevant question: Why does my MacBook Pro take so long to go to sleep?

Deja vu: http://forums.macrumors.com/showthread.php?t=1112715
Chrome Canary seems to fix it.