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/include/audio_processing.h

@@ -53,6 +53,18 @@ struct DelayCorrection {
   bool enabled;
 };
 
+// Use to disable the reported system delays. By disabling the reported system
+// delays the echo cancellation algorithm assumes the process and reverse
+// streams to be aligned. This configuration only applies to EchoCancellation
+// and not EchoControlMobile and is set with AudioProcessing::SetExtraOptions().
+// Note that by disabling reported system delays the EchoCancellation may
+// regress in performance.
+struct ReportedDelay {
+  ReportedDelay() : enabled(true) {}
+  explicit ReportedDelay(bool enabled) : enabled(enabled) {}
+  bool enabled;
+};
+
 // Must be provided through AudioProcessing::Create(Confg&). It will have no
 // impact if used with AudioProcessing::SetExtraOptions().
 struct ExperimentalAgc {