By request from thakis@chromium.org, I disabled the -Wno-unused-const-variable setting that is set in Chromium's common.gypi so we can prepare our code for it's removal. This required some cleanup in order to get the code to compile with Clang having the -Wunused-const-variable warning enabled. TEST=all trybots passing BUG=none R=niklas.enbom@webrtc.org Review URL: https://webrtc-codereview.appspot.com/2400004 git-svn-id: http://webrtc.googlecode.com/svn/trunk@4966 4adac7df-926f-26a2-2b94-8c16560cd09d