AGC2 as a new APM sub-module operating with hard-coded gain.

webrtc/modules/audio_processing/agc2/agc2_mock.h

+/*
+ *  Copyright (c) 2017 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.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_PROCESSING_AGC2_AGC2_MOCK_H_
+#define WEBRTC_MODULES_AUDIO_PROCESSING_AGC2_AGC2_MOCK_H_
+
+#include "webrtc/base/checks.h"
+#include "webrtc/modules/audio_processing/agc2/agc2.h"
+#include "webrtc/test/gmock.h"
+
+namespace webrtc {
+namespace test {
+
+class Agc2Mock : Agc2 {

[peah-webrtc, 2017/05/02 11:01:08]

I don't think we need a mock of AGC2. The main advantage that I see of that is
that it would be possible to verify the integration of AGC within APM, but for
the moment we are not able to do that anyway with the other submodules.
Therefore I think it makes sense not to add it at this point.

[AleBzk, 2017/05/02 11:31:54]

Right. Before removing AGC2 interface and its mock, a question.
Do we expect AGC2 to have dependencies we might want to inject? If so, I'd keep
the mock to easily test calls to the outer interface.

[peah-webrtc, 2017/05/02 11:45:20]

I don't think we should have any depencencies if we don't need to. The current
AGC does not have that and I don't see any reason for adding that. Therefore I
think it is better to start simple, and add a mock in the future if need arises.

[AleBzk, 2017/05/02 15:42:51]

Mock removed.

+ public:
+  explicit Agc2Mock(rtc::CriticalSection* crit) {
+    RTC_DCHECK(crit);
+  }
+  ~Agc2Mock() override = default;
+};
+
+}  // namespace test
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AGC2_AGC2_MOCK_H_