Revert 250500 "Add quotes around executable pathes in the mini i..."

Speculative revert to see if this resolves a spike in update failures on
canary.

> Add quotes around executable pathes in the mini installer
> 
> BUG=340387
> TEST=N/A
> 
> Review URL: https://codereview.chromium.org/154113004

TBR=cdn@chromium.org

Review URL: https://codereview.chromium.org/167333002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251369 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251369