Added more keyboard shortcuts for other wizard screens.
Added more keyboard shortcuts for other wizard screens.

BUG=37068
TEST=Boot so that any wizard is shown. Verify that Ctrl-Alt-{n, u, l, a} switch to network, update, login and account screens correspondingly.

Review URL: http://codereview.chromium.org/1696011

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@45584 0039d316-1c4b-4281-b951-d872f2087c98

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