Add the test case to verify that the introduction of the stable devic…

…e id has fixed the following issue: During the mirror mode, if HDMI node is set as non-active node by user's choice, after the device is suspended then resumed, during the suspend/resume, the hdmi node is lost then re-appeared with the different id, the hdmi node becomes the active node, which overrides the user's choice.

With the help of the stable device id, the reappeared hdmi node won't be set to active.

BUG=443014

Review URL: https://codereview.chromium.org/1596743002

Cr-Commit-Position: refs/heads/master@{#370223}

chromeos/audio/cras_audio_handler_unittest.cc

@@ -2609,6 +2609,64 @@ TEST_F(CrasAudioHandlerTest, ActiveNodeLostAfterResume) {
   EXPECT_TRUE(headphone_resumed->active);
 }
 
+// In the mirror mode, when the device resumes after being suspended, the hmdi
+// node will be lost first, then re-appear with a different node id, but with
+// the same stable id. If it is set as the non-active node  by user before
+// suspend/resume, it should remain inactive after the device resumes even
+// if it has a higher priority than the current active node.
+// crbug.com/443014.
+TEST_F(CrasAudioHandlerTest, HDMIRemainInactiveAfterSuspendResume) {
+  AudioNodeList audio_nodes;
+  AudioNode internal_speaker(kInternalSpeaker);
+  audio_nodes.push_back(internal_speaker);
+  AudioNode hdmi_output(kHDMIOutput);
+  audio_nodes.push_back(hdmi_output);
+  SetUpCrasAudioHandler(audio_nodes);
+
+  // Verify the hdmi is selected as the active output since it has a higher
+  // priority.
+  AudioDeviceList audio_devices;
+  cras_audio_handler_->GetAudioDevices(&audio_devices);
+  EXPECT_EQ(audio_nodes.size(), audio_devices.size());
+  EXPECT_EQ(hdmi_output.id, cras_audio_handler_->GetPrimaryActiveOutputNode());
+
+  // Manually set the active output to internal speaker.
+  cras_audio_handler_->SwitchToDevice(AudioDevice(internal_speaker), true);
+  EXPECT_EQ(internal_speaker.id,
+            cras_audio_handler_->GetPrimaryActiveOutputNode());
+
+  // Simulate the suspend and resume of the device during mirror mode. The HDMI
+  // node will be lost first.
+  audio_nodes.clear();
+  internal_speaker.active = true;
+  audio_nodes.push_back(internal_speaker);
+  ChangeAudioNodes(audio_nodes);
+
+  // Verify the HDMI node is lost, and internal speaker is still the active
+  // node.
+  cras_audio_handler_->GetAudioDevices(&audio_devices);
+  EXPECT_EQ(1u, audio_devices.size());
+  EXPECT_EQ(internal_speaker.id,
+            cras_audio_handler_->GetPrimaryActiveOutputNode());
+
+  // Simulate the re-appearing of the hdmi node, which comes with a new id,
+  // but the same stable device id.
+  AudioNode hdmi_output_2(hdmi_output);
+  hdmi_output_2.id = 20006;
+  hdmi_output_2.plugged_time = internal_speaker.plugged_time + 100;
+  audio_nodes.push_back(hdmi_output_2);
+  EXPECT_NE(hdmi_output.id, hdmi_output_2.id);
+  EXPECT_EQ(hdmi_output.stable_device_id, hdmi_output_2.stable_device_id);
+  ChangeAudioNodes(audio_nodes);
+
+  // Verify the hdmi node is not set the active, and the current active node
+  // , the internal speaker, remains active.
+  cras_audio_handler_->GetAudioDevices(&audio_devices);
+  EXPECT_EQ(2u, audio_devices.size());
+  EXPECT_EQ(internal_speaker.id,
+            cras_audio_handler_->GetPrimaryActiveOutputNode());
+}
+
 // Test the case in which there are two NodesChanged signal for discovering
 // output devices, and there is race between NodesChange and SetActiveOutput
 // during this process. See crbug.com/478968.