Follow-up: Remove old DelayCorrection AEC config

talk/app/webrtc/mediaconstraintsinterface.cc

 /*
  * libjingle
  * Copyright 2013 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 32 matching lines @@
 const char MediaConstraintsInterface::kMaxHeight[] = "maxHeight";
 const char MediaConstraintsInterface::kMinHeight[] = "minHeight";
 const char MediaConstraintsInterface::kMaxFrameRate[] = "maxFrameRate";
 const char MediaConstraintsInterface::kMinFrameRate[] = "minFrameRate";
 
 // Audio constraints.
 const char MediaConstraintsInterface::kEchoCancellation[] =
     "googEchoCancellation";
 const char MediaConstraintsInterface::kGoogEchoCancellation[] =
     "googEchoCancellation";
-const char MediaConstraintsInterface::kExperimentalEchoCancellation[] =
-    "googEchoCancellation2";
 const char MediaConstraintsInterface::kExtendedFilterEchoCancellation[] =
     "googEchoCancellation2";
 const char MediaConstraintsInterface::kDAEchoCancellation[] =
     "googDAEchoCancellation";
 const char MediaConstraintsInterface::kAutoGainControl[] =
     "googAutoGainControl";
 const char MediaConstraintsInterface::kExperimentalAutoGainControl[] =
     "googAutoGainControl2";
 const char MediaConstraintsInterface::kNoiseSuppression[] =
     "googNoiseSuppression";
@@ skipping 95 matching lines @@
       ++*mandatory_constraints;
     return rtc::FromString(string_value, value);
   }
   if (constraints->GetOptional().FindFirst(key, &string_value)) {
     return rtc::FromString(string_value, value);
   }
   return false;
 }
 
 }  // namespace webrtc