Hotword: Check for a speaker model before launching the opt-in flow

chrome/browser/search/hotword_service.h

Index: chrome/browser/search/hotword_service.h
diff --git a/chrome/browser/search/hotword_service.h b/chrome/browser/search/hotword_service.h
index 2c0e086ba12c99f80ae2c522cc5e681ecea7649f..120e4681f27e3e38b5c97fe344e756025d973bd8 100644
--- a/chrome/browser/search/hotword_service.h
+++ b/chrome/browser/search/hotword_service.h
@@ -137,18 +137,26 @@ class HotwordService : public extensions::ExtensionRegistryObserver,
   // These methods are for launching, and getting and setting the launch mode of
   // the Hotword Audio Verification App.
   //
-  // TODO(kcarattini): Remove this when
-  // https://code.google.com/p/chromium/issues/detail?id=165573 is fixed,
-  // at which time we can simply launch the app in the given mode instead of
-  // having to check for it here.
+  // OptIntoHotwording first determines if the app needs to be launched, and if
+  // so, launches the app (if Audio History is on and a speaker model exists,
+  // then we don't need to launch the app).
+  //
+  // LaunchHotwordAudioVerificationApp launches the app without the above
+  // check in the specified |launch_mode|.
   enum LaunchMode {
     HOTWORD_ONLY,
     HOTWORD_AND_AUDIO_HISTORY,
     RETRAIN
   };
+  void OptIntoHotwording(const LaunchMode& launch_mode);

[Anand Mistry (off Chromium), 2015/03/23 03:12:24]

Why is LaunchMode passed as a reference when it's an enum value?

[James Hawkins, 2015/03/23 14:53:40]

It's safe in that we don't make the assumption that the enum value is of a
simple (small) type.

[Anand Mistry (off Chromium), 2015/03/23 23:31:51]

C++ defines the underlying type of an enum to be int, unless you specify a
different one, which C++11 allows. To me, passing an enum as a reference seems
completely wrong. Possible and perfectly valid, but feels very wrong.

But now I'm just arguing. So Kendra, feel free to ignore my ranting.

   void LaunchHotwordAudioVerificationApp(const LaunchMode& launch_mode);
   virtual LaunchMode GetHotwordAudioVerificationLaunchMode();
 
+  // Called when the SpeakerModelExists request is complete. Either
+  // sets the always-on hotword pref to true, or launches the Hotword
+  // Audio Verification App, depending on the value of |exists|.
+  void SpeakerModelExistsComplete(bool exists);
+
   // These methods control the speaker training communication between
   // the Hotword Audio Verification App and the Hotword Extension that
   // contains the NaCl module.