audio_processing/aec: make delay estimator aware of starving farend buffer

webrtc/modules/audio_processing/aec/echo_cancellation.c

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 700 matching lines @@
         // to the buffer and no delay compensation nor AEC processing
         // has been done.
         WebRtcAec_MoveFarReadPtr(aecpc->aec, overhead_elements);
 
         // Enable the AEC
         aecpc->startup_phase = 0;
       }
     }
   } else {
     // AEC is enabled.
-    if (WebRtcAec_reported_delay_enabled(aecpc->aec)) {
-      EstBufDelayNormal(aecpc);
-    }
+    EstBufDelayNormal(aecpc);
 
     // Call the AEC.
     // TODO(bjornv): Re-structure such that we don't have to pass
     // |aecpc->knownDelay| as input. Change name to something like
     // |system_buffer_diff|.
     WebRtcAec_ProcessFrames(aecpc->aec,
                             nearend,
                             num_bands,
                             nrOfSamples,
                             aecpc->knownDelay,
@@ skipping 54 matching lines @@
     // conservative and scale by 2. On Android we use a fixed delay and
     // therefore there is no need to scale the target_delay.
     target_delay /= 2;
 #endif
     int overhead_elements =
         (WebRtcAec_system_delay(self->aec) - target_delay) / PART_LEN;
     WebRtcAec_MoveFarReadPtr(self->aec, overhead_elements);
     self->startup_phase = 0;
   }
 
-  if (WebRtcAec_reported_delay_enabled(self->aec)) {
-    EstBufDelayExtended(self);
-  }
+  EstBufDelayExtended(self);
 
   {
     // |delay_diff_offset| gives us the option to manually rewind the delay on
     // very low delay platforms which can't be expressed purely through
     // |reported_delay_ms|.
     const int adjusted_known_delay =
         WEBRTC_SPL_MAX(0, self->knownDelay + delay_diff_offset);
 
     WebRtcAec_ProcessFrames(self->aec,
                             near,
@@ skipping 103 matching lines @@
     }
   } else {
     self->timeForDelayChange = 0;
   }
   self->lastDelayDiff = delay_difference;
 
   if (self->timeForDelayChange > 25) {
     self->knownDelay = WEBRTC_SPL_MAX((int)self->filtDelay - 256, 0);
   }
 }