Add browser test for getusermedia and unavailable audio device.

media/audio/audio_manager_base.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_manager_base.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/macros.h"
@@ skipping 415 matching lines @@
     return buffer_size;
 
   return 0;
 }
 
 std::unique_ptr<AudioLog> AudioManagerBase::CreateAudioLog(
     AudioLogFactory::AudioComponent component) {
   return audio_log_factory_->CreateAudioLog(component);
 }
 
+void AudioManagerBase::SetMaxStreamCountForTesting(int max_input,
+                                                   int max_output) {
+  max_num_output_streams_ = max_output;
+  max_num_input_streams_ = max_input;
+}
+
 }  // namespace media