Fix occurrences of const typed declaration without initialization

This fixes compilation errors as the following:

error: constructor must explicitly initialize the const member

BUG=506663
R=aluebs@webrtc.org, tommi@webrtc.org

Signed-off-by: Eduardo Lima (Etrunko) <eduardo.lima@intel.com>

Review URL: https://codereview.webrtc.org/1222233002

Cr-Commit-Position: refs/heads/master@{#9538}
2 files changed