Add UMA stats for AEC filter divergence metric.

content/renderer/media/media_stream_audio_processor.h

 // Copyright 2013 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 CONTENT_RENDERER_MEDIA_MEDIA_STREAM_AUDIO_PROCESSOR_H_
 #define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_AUDIO_PROCESSOR_H_
 
 #include "base/atomicops.h"
 #include "base/files/file.h"
 #include "base/gtest_prod_util.h"
@@ skipping 135 matching lines @@
   // Called by ProcessAndConsumeData().
   // Returns the new microphone volume in the range of |0, 255].
   // When the volume does not need to be updated, it returns 0.
   int ProcessData(const float* const* process_ptrs,
                   int process_frames,
                   base::TimeDelta capture_delay,
                   int volume,
                   bool key_pressed,
                   float* const* output_ptrs);
 
+  // Update AEC stats. Called on the main render thread.
+  void UpdateAecStats();
+
   // Cached value for the render delay latency. This member is accessed by
   // both the capture audio thread and the render audio thread.
   base::subtle::Atomic32 render_delay_ms_;
 
   // Module to detect and report (to UMA) bit exact audio repetition.
   std::unique_ptr<AudioRepetitionDetector> audio_repetition_detector_;
 
   // Module to handle processing and format conversion.
   std::unique_ptr<webrtc::AudioProcessing> audio_processing_;
 
@@ skipping 17 matching lines @@
   // lifetime of RenderThread.
   WebRtcPlayoutDataSource* playout_data_source_;
 
   // Used to DCHECK that some methods are called on the main render thread.
   base::ThreadChecker main_thread_checker_;
   // Used to DCHECK that some methods are called on the capture audio thread.
   base::ThreadChecker capture_thread_checker_;
   // Used to DCHECK that some methods are called on the render audio thread.
   base::ThreadChecker render_thread_checker_;
 
+  // Message loop for the main render thread. We're assuming that we're created
+  // on the main render thread.
+  base::MessageLoop* main_thread_message_loop_;
+
   // Flag to enable stereo channel mirroring.
   bool audio_mirroring_;
 
+  // Typing detector. |typing_detected_| is used to show the result of typing
+  // detection. It can be accessed by the capture audio thread and by the
+  // libjingle thread which calls GetStats().
   std::unique_ptr<webrtc::TypingDetection> typing_detector_;
-  // This flag is used to show the result of typing detection.
-  // It can be accessed by the capture audio thread and by the libjingle thread
-  // which calls GetStats().
   base::subtle::Atomic32 typing_detected_;
 
   // Communication with browser for AEC dump.
   scoped_refptr<AecDumpMessageFilter> aec_dump_message_filter_;
 
   // Flag to avoid executing Stop() more than once.
   bool stopped_;
 
-  // Object for logging echo information when the AEC is enabled. Accessible by
-  // the libjingle thread through GetStats().
+  // Object for logging UMA stats for echo information when the AEC is enabled.
+  // Accessed on the main render thread.
   std::unique_ptr<EchoInformation> echo_information_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamAudioProcessor);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_AUDIO_PROCESSOR_H_