[Hotword] Implement IsHotwordHardwareAvailable() using device types.

chrome/browser/search/hotword_service_factory.cc

 // Copyright 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 "chrome/browser/search/hotword_service_factory.h"
 
 #include "base/command_line.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search/hotword_service.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 
+#if defined(OS_CHROMEOS)
+#include "chromeos/audio/cras_audio_handler.h"
+#endif
+
 using content::BrowserContext;
 using content::BrowserThread;
 
 // static
 HotwordService* HotwordServiceFactory::GetForProfile(BrowserContext* context) {
   return static_cast<HotwordService*>(
       GetInstance()->GetServiceForBrowserContext(context, true));
 }
 
 // static
 HotwordServiceFactory* HotwordServiceFactory::GetInstance() {
   return Singleton<HotwordServiceFactory>::get();
 }
 
 // static
 bool HotwordServiceFactory::IsServiceAvailable(BrowserContext* context) {
   HotwordService* hotword_service = GetForProfile(context);
   return hotword_service && hotword_service->IsServiceAvailable();
 }
 
 // static
 bool HotwordServiceFactory::IsHotwordAllowed(BrowserContext* context) {
   HotwordService* hotword_service = GetForProfile(context);
   return hotword_service && hotword_service->IsHotwordAllowed();
 }
 
 // static
 bool HotwordServiceFactory::IsHotwordHardwareAvailable() {
-  // TODO(rlp, dgreid): return has_hotword_hardware()
-  // Fill in once the hardware has the correct interface implemented.
-  // In the meantime, this function can be used to get other parts moving
-  // based on a flag.
+#if defined(OS_CHROMEOS)
+  chromeos::AudioDeviceList devices;
+  chromeos::CrasAudioHandler::Get()->GetAudioDevices(&devices);
+  for (size_t i = 0; i < devices.size(); ++i) {
+    if (devices[i].type == chromeos::AUDIO_TYPE_AOKR)

[jennyz, 2014/12/13 00:05:01]

By the way, do you know if this device is an input or output device? 

[dgreid, 2014/12/13 00:06:11]

always input.

[jennyz, 2014/12/13 00:08:14]

How about
DCHECK(devices[i].is_input)?

[jennyz, 2014/12/13 00:17:36]

I think it makes more sense to DCHECK it is input device here.

[rpetterson, 2014/12/13 00:56:27]

Ah, got it. I got the lines confused before. Done.

+      return true;
+  }
+#endif
   CommandLine* command_line = CommandLine::ForCurrentProcess();
   return command_line->HasSwitch(switches::kEnableExperimentalHotwordHardware);
 }
 
 // static
 int HotwordServiceFactory::GetCurrentError(BrowserContext* context) {
   HotwordService* hotword_service = GetForProfile(context);
   if (!hotword_service)
     return 0;
   return hotword_service->error_message();
@@ skipping 67 matching lines @@
                              user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
   prefs->RegisterBooleanPref(prefs::kHotwordAlwaysOnNotificationSeen,
                              false,
                              user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 }
 
 KeyedService* HotwordServiceFactory::BuildServiceInstanceFor(
     BrowserContext* context) const {
   return new HotwordService(Profile::FromBrowserContext(context));
 }