Rename valgrind_layout to valgrind_webkit

This will allow for more uniform buildbot factories

BUG=none
TEST=none


Review URL: http://codereview.chromium.org/6685121

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@78927 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed