Enable -Wformat-security warning and cleanup GYP.

Enable the -Wformat-security and -Wformat warnings for talk/.

Remove *.def and *.h.pump files from webrtc/base/base.gyp since they're not supported by some tools.

BUG=4242
R=henrika@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/49969004

Cr-Commit-Position: refs/heads/master@{#9191}
2 files changed