Add WebKit.gyp:generate_devtools_zip to the All target.
Add WebKit.gyp:generate_devtools_zip to the All target.

This is needed so the clobber builders will generate the devtools zip
that gets archived by the bots.

BUG=113948


Review URL: http://codereview.chromium.org/9395025

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@121992 0039d316-1c4b-4281-b951-d872f2087c98

adobe/chromium,ropik/chromium,adobe/chromium,adobe/chromium,gavinp/chromium,ropik/chromium,gavinp/chromium,yitian134/chromium,ropik/chromium,ropik/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,ropik/chromium,gavinp/chromium,adobe/chromium,yitian134/chromium,yitian134/chromium,gavinp/chromium,gavinp/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,adobe/chromium,gavinp/chromium,yitian134/chromium,adobe/chromium,gavinp/chromium,gavinp/chromium,yitian134/chromium,yitian134/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,gavinp/chromium,gavinp/chromium,ropik/chromium,adobe/chromium,yitian134/chromium,adobe/chromium