Take out bogus DCHECK
Take out bogus DCHECK

This DCHECK is valid only within the browser itself -- it doesn't work
for tests, etc, which have different default plugins.

BUG=none
TEST=ran test_shell_tests and test_shell
TBR=piman@chromium.org

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@62267 0039d316-1c4b-4281-b951-d872f2087c98

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