Able to query an active device on LaCrOS

Make lacros-chrome able to query the id of an active device.

BUG=b:173113548

Change-Id: I0169592ddf95d8cadca6806ac1a671eb06bc87fc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2536662
Commit-Queue: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#828555}

media/audio/cras/audio_manager_cras.cc

@@ -157,12 +157,18 @@ AudioParameters AudioManagerCras::GetPreferredOutputStreamParameters(
 }
 
 uint64_t AudioManagerCras::GetPrimaryActiveInputNode() {
-  DCHECK(GetTaskRunner()->BelongsToCurrentThread());
+  for (const auto& device : CrasGetAudioDevices(DeviceType::kInput)) {
+    if (device.active)
+      return device.id;
+  }
   return 0;
 }
 
 uint64_t AudioManagerCras::GetPrimaryActiveOutputNode() {
-  DCHECK(GetTaskRunner()->BelongsToCurrentThread());
+  for (const auto& device : CrasGetAudioDevices(DeviceType::kOutput)) {
+    if (device.active)
+      return device.id;
+  }
   return 0;
 }
 

media/audio/cras/cras_util.cc

@@ -68,6 +68,7 @@ CrasDevice::CrasDevice(const cras_ionode_info* node,
                        DeviceType type)
     : type(type) {
   id = cras_make_node_id(node->iodev_idx, node->ionode_idx);
+  active = node->active;
   name = std::string(node->name);
   // If the name of node is not meaningful, use the device name instead.
   if (name.empty() || name == "(default)")
@@ -101,6 +102,8 @@ CrasDevice::CrasDevice(const std::vector<cras_ionode_info>& nodes,
   } else {
     LOG(WARNING) << "Failed to create virtual device for " << dev->name;
   }
+
+  active = nodes[0].active || nodes[1].active;
 }
 
 std::vector<CrasDevice> CrasGetAudioDevices(DeviceType type) {

media/audio/cras/cras_util.h

@@ -25,6 +25,7 @@ struct CrasDevice {
                       DeviceType type);
   DeviceType type;
   uint64_t id;
+  int32_t active;
   std::string name;
 };