Make boottime delay not block file thread BUG=None TEST=Boot on ARM...boottimes shouldn't display but chrome should      still work. We will be stating a file every half second though      until /tmp/uptime-login-prompt-ready is emited.
Make boottime delay not block file thread
BUG=None
TEST=Boot on ARM...boottimes shouldn't display but chrome should
     still work. We will be stating a file every half second though
     until /tmp/uptime-login-prompt-ready is emited.

Review URL: http://codereview.chromium.org/2007010

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@47097 0039d316-1c4b-4281-b951-d872f2087c98

adobe/chromium,ropik/chromium,ropik/chromium,yitian134/chromium,gavinp/chromium,adobe/chromium,adobe/chromium,ropik/chromium,gavinp/chromium,ropik/chromium,Crystalnix/house-of-life-chromium,ropik/chromium,gavinp/chromium,gavinp/chromium,ropik/chromium,gavinp/chromium,adobe/chromium,Crystalnix/house-of-life-chromium,Crystalnix/house-of-life-chromium,adobe/chromium,Crystalnix/house-of-life-chromium,yitian134/chromium,adobe/chromium,yitian134/chromium,yitian134/chromium,Crystalnix/house-of-life-chromium,yitian134/chromium,yitian134/chromium,gavinp/chromium,yitian134/chromium,Crystalnix/house-of-life-chromium,ropik/chromium,Crystalnix/house-of-life-chromium,adobe/chromium,yitian134/chromium,adobe/chromium,gavinp/chromium,gavinp/chromium,adobe/chromium,ropik/chromium,Crystalnix/house-of-life-chromium,Crystalnix/house-of-life-chromium,yitian134/chromium,adobe/chromium,gavinp/chromium,yitian134/chromium,adobe/chromium,ropik/chromium,Crystalnix/house-of-life-chromium,gavinp/chromium,Crystalnix/house-of-life-chromium