Revert "Remove <(webrtc_root) from source file entries."

And the follow-up fix in r8198 that was not sufficient.
Reason: breaks Chromium bots runhooks (GYP).

I will have to try some more to make sure I don't
include test code, since include_tests==0 in Chromium.

TBR=andrew@webrtc.org, tina.legrand@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/37039004

Cr-Commit-Position: refs/heads/master@{#8200}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8200 4adac7df-926f-26a2-2b94-8c16560cd09d
18 files changed