Drop the restriction on same forward and reverse sample rate on the AudioFrame interface of the APM

webrtc/modules/audio_processing/audio_processing_impl_unittest.cc

 /*
  *  Copyright (c) 2014 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 47 matching lines @@
 
   // New number of channels.
   frame.num_channels_ = 2;
   EXPECT_CALL(mock, InitializeLocked())
       .Times(2);
   EXPECT_NOERR(mock.ProcessStream(&frame));
   // ProcessStream sets num_channels_ == num_output_channels.
   frame.num_channels_ = 2;
   EXPECT_NOERR(mock.AnalyzeReverseStream(&frame));
 
-  // A new sample rate passed to AnalyzeReverseStream should be an error and
-  // not cause an init.
+  // A new sample rate passed to AnalyzeReverseStream should cause an init.
   SetFrameSampleRate(&frame, 16000);
-  EXPECT_CALL(mock, InitializeLocked())
-      .Times(0);
-  EXPECT_EQ(mock.kBadSampleRateError, mock.AnalyzeReverseStream(&frame));
+  EXPECT_CALL(mock, InitializeLocked()).Times(1);
+  EXPECT_NOERR(mock.AnalyzeReverseStream(&frame));
 }
 
 }  // namespace webrtc