Add StringPiece to the scons build.
Add StringPiece to the scons build.

TBR=sgk

git-svn-id: http://src.chromium.org/svn/trunk/src@313 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 6eb89daf13e8d0c4182e3040470161539e285925
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser