Re-implement audio capturing based on the AudioService API (fixes issue #2755)

libcef/browser/audio_capturer.h

@@ -0,0 +1,53 @@
+// Copyright (c) 2019 The Chromium Embedded Framework Authors.
+// Portions copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CEF_LIBCEF_BROWSER_AUDIO_CAPTURER_H_
+#define CEF_LIBCEF_BROWSER_AUDIO_CAPTURER_H_
+#pragma once
+
+#include "include/internal/cef_ptr.h"
+#include "include/internal/cef_types_wrappers.h"
+
+#include "media/base/audio_capturer_source.h"
+
+namespace content {
+class AudioLoopbackStreamCreator;
+}  // namespace content
+
+namespace media {
+class AudioInputDevice;
+}  // namespace media
+
+class CefAudioHandler;
+class CefBrowserHostImpl;
+
+class CefAudioCapturer : public media::AudioCapturerSource::CaptureCallback {
+ public:
+  CefAudioCapturer(const CefAudioParameters& params,
+                   CefRefPtr<CefBrowserHostImpl> browser,
+                   CefRefPtr<CefAudioHandler> audio_handler);
+  ~CefAudioCapturer() override;
+
+ private:
+  void OnCaptureStarted() override;
+  void Capture(const media::AudioBus* audio_source,
+               base::TimeTicks audio_capture_time,
+               double volume,
+               bool key_pressed) override;
+  void OnCaptureError(const std::string& message) override;
+  void OnCaptureMuted(bool is_muted) override {}
+
+  void StopStream();
+
+  CefAudioParameters params_;
+  CefRefPtr<CefBrowserHostImpl> browser_;
+  CefRefPtr<CefAudioHandler> audio_handler_;
+  std::unique_ptr<content::AudioLoopbackStreamCreator> audio_stream_creator_;
+  scoped_refptr<media::AudioInputDevice> audio_input_device_;
+  bool capturing_ = false;
+  int channels_ = 0;
+};
+
+#endif  // CEF_LIBCEF_BROWSER_AUDIO_CAPTURER_H_