Roll chromium_revision 229708:231713

Recent changes in how the build dir is used for bots
(see https://codereview.chromium.org/38873003 for details)
requires us to roll to a more recent version
of Chromium to get our android_apk trybot back into
a working state.

This roll needs to be landed at the same time as the
client.webrtc and tryserver.webrtc masters are updated
with the changes in https://codereview.chromium.org/53283002

TEST=trybots passing (except the iOS ones since they require
the above change to be applied to be able to compile)
BUG=2560
R=fischman@webrtc.org, niklas.enbom@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/3159004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5074 4adac7df-926f-26a2-2b94-8c16560cd09d