Simplify AudioInputRendererHost IPC interface.

media/audio/audio_input_device.cc

 // Copyright (c) 2012 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.
 
 #include "media/audio/audio_input_device.h"
 
 #include <stdint.h>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 137 matching lines @@
   DCHECK(!audio_thread_);
   audio_callback_.reset(new AudioInputDevice::AudioThreadCallback(
       audio_parameters_, handle, length, total_segments, callback_));
   audio_thread_.reset(new AudioDeviceThread(audio_callback_.get(),
                                             socket_handle, "AudioInputDevice"));
 
   state_ = RECORDING;
   ipc_->RecordStream();
 }
 
-void AudioInputDevice::OnVolume(double volume) {
-  NOTIMPLEMENTED();
-}
-
-void AudioInputDevice::OnStateChanged(
-    AudioInputIPCDelegateState state) {
+void AudioInputDevice::OnError() {

[tommi (sloooow) - chröme, 2017/01/09 09:25:19]

Nice, OnError makes a lot more sense :)

   DCHECK(task_runner()->BelongsToCurrentThread());
 
   // Do nothing if the stream has been closed.
   if (state_ < CREATING_STREAM)
     return;
 
-  // TODO(miu): Clean-up inconsistent and incomplete handling here.
-  // http://crbug.com/180640
-  switch (state) {
-    case AUDIO_INPUT_IPC_DELEGATE_STATE_STOPPED:
-      ShutDownOnIOThread();
-      break;
-    case AUDIO_INPUT_IPC_DELEGATE_STATE_RECORDING:
-      NOTIMPLEMENTED();
-      break;
-    case AUDIO_INPUT_IPC_DELEGATE_STATE_ERROR:
-      DLOG(WARNING) << "AudioInputDevice::OnStateChanged(ERROR)";
-      if (state_ == CREATING_STREAM) {
-        // At this point, we haven't attempted to start the audio thread.
-        // Accessing the hardware might have failed or we may have reached
-        // the limit of the number of allowed concurrent streams.
-        // We must report the error to the |callback_| so that a potential
-        // audio source object will enter the correct state (e.g. 'ended' for
-        // a local audio source).
-        callback_->OnCaptureError(
-            "Maximum allowed input device limit reached or OS failure.");
-      } else {
-        // Don't dereference the callback object if the audio thread
-        // is stopped or stopping.  That could mean that the callback
-        // object has been deleted.
-        // TODO(tommi): Add an explicit contract for clearing the callback
-        // object.  Possibly require calling Initialize again or provide
-        // a callback object via Start() and clear it in Stop().
-        base::AutoLock auto_lock_(audio_thread_lock_);
-        if (audio_thread_)
-          callback_->OnCaptureError("AUDIO_INPUT_IPC_DELEGATE_STATE_ERROR");
-      }
-      break;
-    default:
-      NOTREACHED();
-      break;
+  DLOG(WARNING) << "AudioInputDevice::OnStateChanged(ERROR)";
+  if (state_ == CREATING_STREAM) {
+    // At this point, we haven't attempted to start the audio thread.
+    // Accessing the hardware might have failed or we may have reached
+    // the limit of the number of allowed concurrent streams.
+    // We must report the error to the |callback_| so that a potential
+    // audio source object will enter the correct state (e.g. 'ended' for
+    // a local audio source).
+    callback_->OnCaptureError(
+        "Maximum allowed input device limit reached or OS failure.");
+  } else {
+    // Don't dereference the callback object if the audio thread
+    // is stopped or stopping.  That could mean that the callback
+    // object has been deleted.
+    // TODO(tommi): Add an explicit contract for clearing the callback
+    // object.  Possibly require calling Initialize again or provide
+    // a callback object via Start() and clear it in Stop().
+    base::AutoLock auto_lock_(audio_thread_lock_);
+    if (audio_thread_)
+      callback_->OnCaptureError("IPC delegate state error.");
   }
 }
 
 void AudioInputDevice::OnIPCClosed() {
   DCHECK(task_runner()->BelongsToCurrentThread());
   state_ = IPC_CLOSED;
   ipc_.reset();
 }
 
 AudioInputDevice::~AudioInputDevice() {}
@@ skipping 137 matching lines @@
   capture_callback_->Capture(
       audio_bus,
       buffer->params.hardware_delay_bytes / bytes_per_ms_,  // Delay in ms
       buffer->params.volume, buffer->params.key_pressed);
 
   if (++current_segment_id_ >= total_segments_)
     current_segment_id_ = 0;
 }
 
 }  // namespace media