Fix getUserMedia so that failure is reported for invalid audio sources.

content/renderer/media/local_media_stream_audio_source.cc

 // Copyright 2016 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 "content/renderer/media/local_media_stream_audio_source.h"
 
 #include "content/common/media/media_stream_options.h"
 #include "content/renderer/media/audio_device_factory.h"
 #include "content/renderer/render_frame_impl.h"
 
 namespace content {
 
 LocalMediaStreamAudioSource::LocalMediaStreamAudioSource(
     int consumer_render_frame_id,
-    const StreamDeviceInfo& device_info)
+    const StreamDeviceInfo& device_info,
+    const ConstraintsCallback& started_callback)
     : MediaStreamAudioSource(true /* is_local_source */),
-      consumer_render_frame_id_(consumer_render_frame_id) {
+      consumer_render_frame_id_(consumer_render_frame_id),
+      started_callback_(started_callback) {
   DVLOG(1) << "LocalMediaStreamAudioSource::LocalMediaStreamAudioSource()";
   MediaStreamSource::SetDeviceInfo(device_info);
 
   // If the device buffer size was not provided, use a default.
   int frames_per_buffer = device_info.device.input.frames_per_buffer;
   if (frames_per_buffer <= 0) {
     // TODO(miu): Like in ProcessedLocalAudioSource::GetBufferSize(), we should
     // re-evaluate whether Android needs special treatment here. Or, perhaps we
     // should just DCHECK_GT(device_info...frames_per_buffer, 0)?
     // http://crbug.com/638081
@@ skipping 49 matching lines @@
 
   source_->Stop();
   source_ = nullptr;
 
   VLOG(1) << "Stopped local audio input device (session_id="
           << device_info().session_id << ") for render frame "
           << consumer_render_frame_id_ << " with audio parameters={"
           << GetAudioParameters().AsHumanReadableString() << "}.";
 }
 
+void LocalMediaStreamAudioSource::OnCaptureStarted() {
+  started_callback_.Run(this, MEDIA_DEVICE_OK, "");
+}
+
 void LocalMediaStreamAudioSource::Capture(const media::AudioBus* audio_bus,
                                           int audio_delay_milliseconds,
                                           double volume,
                                           bool key_pressed) {
   DCHECK(audio_bus);
   // TODO(miu): Plumbing is needed to determine the actual capture timestamp
   // of the audio, instead of just snapshotting TimeTicks::Now(), for proper
   // audio/video sync. http://crbug.com/335335
   MediaStreamAudioSource::DeliverDataToTracks(
       *audio_bus,
       base::TimeTicks::Now() -
       base::TimeDelta::FromMilliseconds(audio_delay_milliseconds));
 }
 
 void LocalMediaStreamAudioSource::OnCaptureError(const std::string& why) {
   StopSourceOnError(why);
 }
 
 }  // namespace content