Remove AudioDeviceObserver and make ADM not inherit from the Module interface.

test/mock_voice_engine.h

 /*
  *  Copyright (c) 2015 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 45 matching lines @@
               .WillRepeatedly(testing::Invoke(
                   [](const std::map<int, SdpAudioFormat>& codecs) {
                     EXPECT_THAT(codecs, testing::IsEmpty());
                   }));
           EXPECT_CALL(*proxy, GetRtpRtcp(testing::_, testing::_))
               .WillRepeatedly(
                   testing::SetArgPointee<0>(GetMockRtpRtcp(channel_id)));
           return proxy;
         }));
 
-    ON_CALL(mock_audio_device_, TimeUntilNextProcess())
-        .WillByDefault(testing::Return(1000));
     ON_CALL(*this, audio_device_module())
         .WillByDefault(testing::Return(&mock_audio_device_));
     ON_CALL(*this, audio_transport())
         .WillByDefault(testing::Return(&mock_audio_transport_));
   }
   virtual ~MockVoiceEngine() /* override */ {
     // Decrease ref count before base class d-tor is called; otherwise it will
     // trigger an assertion.
     --_ref_count;
   }
@@ skipping 44 matching lines @@
 
   std::map<int, std::unique_ptr<MockRtpRtcp>> mock_rtp_rtcps_;
 
   MockAudioDeviceModule mock_audio_device_;
   MockAudioTransport mock_audio_transport_;
 };
 }  // namespace test
 }  // namespace webrtc
 
 #endif  // AUDIO_MOCK_VOICE_ENGINE_H_