Added namespaces in the newly C++ified AEC code

webrtc/modules/audio_processing/aec/echo_cancellation.cc

 /*
  *  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 11 matching lines @@
 
 extern "C" {
 #include "webrtc/common_audio/ring_buffer.h"
 #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
 }
 #include "webrtc/modules/audio_processing/aec/aec_core.h"
 #include "webrtc/modules/audio_processing/aec/aec_resampler.h"
 #include "webrtc/modules/audio_processing/aec/echo_cancellation_internal.h"
 #include "webrtc/typedefs.h"
 
+namespace webrtc {
+
 // Measured delays [ms]
 // Device                Chrome  GTP
 // MacBook Air           10
 // MacBook Retina        10      100
 // MacPro                30?
 //
 // Win7 Desktop          70      80?
 // Win7 T430s            110
 // Win8 T420s            70
 //
@@ skipping 832 matching lines @@
     }
   } else {
     self->timeForDelayChange = 0;
   }
   self->lastDelayDiff = delay_difference;
 
   if (self->timeForDelayChange > 25) {
     self->knownDelay = WEBRTC_SPL_MAX((int)self->filtDelay - 256, 0);
   }
 }
+}  // namespace webrtc