sync-webkit-git: fixes to work on Windows
sync-webkit-git: fixes to work on Windows

You need shell=True on Windows for it to understand PATH.
(Python's subprocess module is confusing: the Windows semantics
are significantly different than the Unix ones.  Either way on
Windows, the command array is flattened and shell-escaped.)

Review URL: http://codereview.chromium.org/3032009

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@53119 0039d316-1c4b-4281-b951-d872f2087c98

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