Refactor hotword device detection

Currently there are code duplication that does similar things to detect
hotword input device. Now we move all the logic into cras_audio_handler
to simplify the code.

Bug: None
Test: locally build and run
Change-Id: I08df6cef18a17dd3c5b2eff6f5b4193aecf0b3e5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1686951Reviewed-by: Jenny Zhang <jennyz@chromium.org>
Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Tao Wu <wutao@chromium.org>
Commit-Queue: Xiaohui Chen <xiaohuic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#675764}

chrome/browser/ui/webui/chromeos/assistant_optin/assistant_optin_utils.cc

@@ -4,6 +4,8 @@
 
 #include "chrome/browser/ui/webui/chromeos/assistant_optin/assistant_optin_utils.h"
 
+#include <utility>
+
 #include "base/metrics/histogram_macros.h"
 #include "chrome/browser/consent_auditor/consent_auditor_factory.h"
 #include "chrome/browser/signin/identity_manager_factory.h"
@@ -266,16 +268,7 @@ void RecordActivityControlConsent(Profile* profile,
 }
 
 bool IsHotwordDspAvailable() {
-  chromeos::AudioDeviceList devices;
-  chromeos::CrasAudioHandler::Get()->GetAudioDevices(&devices);
-  for (const chromeos::AudioDevice& device : devices) {
-    if (device.type == chromeos::AUDIO_TYPE_HOTWORD) {
-      VLOG(1) << "Hotword dsp device detected.";
-      return true;
-    }
-  }
-  VLOG(1) << "No hotword dsp device detected.";
-  return false;
+  return chromeos::CrasAudioHandler::Get()->HasHotwordDevice();
 }
 
 bool IsVoiceMatchEnabled(const PrefService* prefs) {

chromeos/audio/cras_audio_handler.cc

@@ -10,7 +10,7 @@
 #include <algorithm>
 #include <cmath>
 #include <set>
-#include <string>
+#include <utility>
 #include <vector>
 
 #include "base/bind.h"
@@ -20,6 +20,7 @@
 #include "base/system/sys_info.h"
 #include "base/system/system_monitor.h"
 #include "base/threading/thread_task_runner_handle.h"
+#include "chromeos/audio/audio_device.h"
 #include "chromeos/audio/audio_devices_pref_handler_stub.h"
 #include "services/media_session/public/mojom/constants.mojom.h"
 #include "services/media_session/public/mojom/media_controller.mojom.h"
@@ -242,6 +243,10 @@ bool CrasAudioHandler::HasKeyboardMic() {
   return GetKeyboardMic() != nullptr;
 }
 
+bool CrasAudioHandler::HasHotwordDevice() {
+  return GetHotwordDevice() != nullptr;
+}
+
 bool CrasAudioHandler::IsOutputMuted() {
   return output_mute_on_;
 }
@@ -788,6 +793,15 @@ const AudioDevice* CrasAudioHandler::GetKeyboardMic() const {
   return nullptr;
 }
 
+const AudioDevice* CrasAudioHandler::GetHotwordDevice() const {
+  for (const auto& item : audio_devices_) {
+    const AudioDevice& device = item.second;
+    if (device.is_input && device.type == AUDIO_TYPE_HOTWORD)
+      return &device;
+  }
+  return nullptr;
+}
+
 void CrasAudioHandler::SetupAudioInputState() {
   // Set the initial audio state to the ones read from audio prefs.
   const AudioDevice* device = GetDeviceFromId(active_input_node_id_);

chromeos/audio/cras_audio_handler.h

@@ -9,6 +9,7 @@
 #include <stdint.h>
 
 #include <queue>
+#include <string>
 #include <vector>
 
 #include "base/component_export.h"
@@ -132,6 +133,9 @@ class COMPONENT_EXPORT(CHROMEOS_AUDIO) CrasAudioHandler
   // Returns true if keyboard mic exists.
   bool HasKeyboardMic();
 
+  // Returns true if hotword input device exists.
+  bool HasHotwordDevice();
+
   // Returns true if audio output is muted for the system.
   bool IsOutputMuted();
 
@@ -351,6 +355,8 @@ class COMPONENT_EXPORT(CHROMEOS_AUDIO) CrasAudioHandler
       uint64_t stable_device_id) const;
   const AudioDevice* GetKeyboardMic() const;
 
+  const AudioDevice* GetHotwordDevice() const;
+
   // Initializes audio state, which should only be called when CrasAudioHandler
   // is created or cras audio client is restarted.
   void InitializeAudioState();

chromeos/services/assistant/service.cc

@@ -98,14 +98,7 @@ void Service::RequestAccessToken() {
 }
 
 bool Service::ShouldEnableHotword() {
-  bool dsp_available = false;
-  chromeos::AudioDeviceList devices;
-  chromeos::CrasAudioHandler::Get()->GetAudioDevices(&devices);
-  for (const chromeos::AudioDevice& device : devices) {
-    if (device.type == chromeos::AUDIO_TYPE_HOTWORD) {
-      dsp_available = true;
-    }
-  }
+  bool dsp_available = chromeos::CrasAudioHandler::Get()->HasHotwordDevice();
 
   // Disable hotword if hotword is not set to always on and power source is not
   // connected.

content/browser/renderer_host/media/media_stream_manager.cc

@@ -134,15 +134,9 @@ void EnableHotwordEffect(const StreamControls& controls, int* effects) {
   DCHECK(effects);
   if (controls.hotword_enabled) {
 #if defined(OS_CHROMEOS)
-    chromeos::AudioDeviceList devices;
-    chromeos::CrasAudioHandler::Get()->GetAudioDevices(&devices);
     // Only enable if a hotword device exists.
-    for (const chromeos::AudioDevice& device : devices) {
-      if (device.type == chromeos::AUDIO_TYPE_HOTWORD) {
-        DCHECK(device.is_input);
+    if (chromeos::CrasAudioHandler::Get()->HasHotwordDevice())
       *effects |= media::AudioParameters::HOTWORD;
-      }
-    }
 #endif
   }
 }