Reset the active audio node id once all of the devices are gone.

chromeos/audio/cras_audio_handler_unittest.cc

 // Copyright (c) 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.
 
 #include "chromeos/audio/cras_audio_handler.h"
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/values.h"
@@ skipping 200 matching lines @@
 
   void reset_active_output_node_changed_count() {
     active_output_node_changed_count_ = 0;
   }
 
   int active_input_node_changed_count() const {
     return active_input_node_changed_count_;
   }
 
   void reset_active_input_node_changed_count() {
-    active_output_node_changed_count_ = 0;
+    active_input_node_changed_count_ = 0;
   }
 
   int audio_nodes_changed_count() const {
     return audio_nodes_changed_count_;
   }
 
   int output_mute_changed_count() const {
     return output_mute_changed_count_;
   }
 
@@ skipping 2045 matching lines @@
   cras_audio_handler_->ChangeActiveNodes(active_nodes);
 
   // Verify the jabra speaker's output is selected as active output, and
   // jabra's input is selected as active input.
   EXPECT_EQ(2, GetActiveDeviceCount());
   EXPECT_EQ(kHDMIOutput.id, cras_audio_handler_->GetPrimaryActiveOutputNode());
   EXPECT_EQ(kUSBJabraSpeakerInput1.id,
             cras_audio_handler_->GetPrimaryActiveInputNode());
 }
 
+TEST_F(CrasAudioHandlerTest, NoMoreAudioInputDevices) {
+  // Some device like chromebox does not have the internal input device. The
+  // active devices should be reset when the user plugs a device and then
+  // unplugs it to such device.
+
+  AudioNodeList audio_nodes;
+  audio_nodes.push_back(kInternalSpeaker);
+  SetUpCrasAudioHandler(audio_nodes);
+
+  EXPECT_EQ(0ULL, cras_audio_handler_->GetPrimaryActiveInputNode());
+
+  audio_nodes.push_back(kMicJack);
+  ChangeAudioNodes(audio_nodes);
+
+  EXPECT_EQ(kMicJack.id, cras_audio_handler_->GetPrimaryActiveInputNode());
+  EXPECT_EQ(1, test_observer_->active_input_node_changed_count());
+  test_observer_->reset_active_input_node_changed_count();
+
+  audio_nodes.pop_back();
+  ChangeAudioNodes(audio_nodes);
+  EXPECT_EQ(0ULL, cras_audio_handler_->GetPrimaryActiveInputNode());
+  EXPECT_EQ(1, test_observer_->active_input_node_changed_count());
+}
+
 }  // namespace chromeos