Notify hotwording extension of microphone state change.

chrome/browser/search/hotword_service_factory.cc

Index: chrome/browser/search/hotword_service_factory.cc
diff --git a/chrome/browser/search/hotword_service_factory.cc b/chrome/browser/search/hotword_service_factory.cc
index bbc10b4f1a22d684fc8ae2709d6b1380db2982b6..7b7284e9bc491096bc23afc4057401ca68aea5d4 100644
--- a/chrome/browser/search/hotword_service_factory.cc
+++ b/chrome/browser/search/hotword_service_factory.cc
@@ -68,45 +68,16 @@ int HotwordServiceFactory::GetCurrentError(BrowserContext* context) {
   return hotword_service->error_message();
 }
 
-// static
-bool HotwordServiceFactory::IsMicrophoneAvailable() {
-  return GetInstance()->microphone_available();
-}
-
-// static
-bool HotwordServiceFactory::IsAudioDeviceStateUpdated() {
-  return GetInstance()->audio_device_state_updated();
-}
-
 HotwordServiceFactory::HotwordServiceFactory()
     : BrowserContextKeyedServiceFactory(
         "HotwordService",
-        BrowserContextDependencyManager::GetInstance()),
-      microphone_available_(false),
-      audio_device_state_updated_(false) {
+        BrowserContextDependencyManager::GetInstance()) {
   // No dependencies.
-
-  // Register with the device observer list to update the microphone
-  // availability.
-  BrowserThread::PostTask(
-      BrowserThread::UI, FROM_HERE,
-      base::Bind(&HotwordServiceFactory::InitializeMicrophoneObserver,
-                 base::Unretained(this)));
 }
 
 HotwordServiceFactory::~HotwordServiceFactory() {
 }
 
-void HotwordServiceFactory::InitializeMicrophoneObserver() {
-  MediaCaptureDevicesDispatcher::GetInstance()->AddObserver(this);
-}
-
-void HotwordServiceFactory::OnUpdateAudioDevices(
-    const content::MediaStreamDevices& devices) {
-  microphone_available_ = !devices.empty();
-  audio_device_state_updated_ = true;
-}
-
 void HotwordServiceFactory::UpdateMicrophoneState() {
   // In order to trigger the monitor, just call getAudioCaptureDevices.
   content::MediaStreamDevices devices =