Disable all protobuf dependent targets when enable_protobuf=0.

BUG=3045
TESTED=builds now when enable_protobuf=0 and modules_unittests still
includes ApmTest.* when enable_protobuf=1.

R=bjornv@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/9879004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5690 4adac7df-926f-26a2-2b94-8c16560cd09d
Fixing incorrect memset.

Found when ENABLE_EXTERNAL_AUTH is enabled in chrome.

TBR=ronghuawu@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/9909004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5691 4adac7df-926f-26a2-2b94-8c16560cd09d
Replace labs with std::abs.

Resolves clang 3.5 warnings on OS X for -Wabsolute-value.

BUG=chromium:351479
R=andrew@webrtc.org, thakis@chromium.org

Review URL: https://webrtc-codereview.appspot.com/9869004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5692 4adac7df-926f-26a2-2b94-8c16560cd09d