modules/audio_processing: Adds a config for reported delays

There are platforms and devices where the reported delays are untrusted and we currently solve that with an extended filter length and a slightly more conservative delay handling.
With this change we give the user the possibility to turn off reported system delay values completely.

- Includes new unit tests.

TESTED=trybots and manual testing
R=aluebs@webrtc.org, kwiberg@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/13629004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6391 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/audio_processing/echo_cancellation_impl.cc

@@ -323,6 +323,7 @@ int EchoCancellationImpl::Initialize() {
 
 void EchoCancellationImpl::SetExtraOptions(const Config& config) {
   delay_correction_enabled_ = config.Get<DelayCorrection>().enabled;
+  reported_delay_enabled_ = config.Get<ReportedDelay>().enabled;
   Configure();
 }