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..bea93292cdaed8b006f3fcfc60ab9846e58f949c 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.
+  // MaybeLaunchHotwordAudioVerificationApp 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 MaybeLaunchHotwordAudioVerificationApp(const LaunchMode& launch_mode);

[James Hawkins, 2015/03/19 22:57:07]

I highly suggest not naming methods MaybeBlah.  It's incredibly confusing, as
it's not clear under what circumstances the method will do Blah without reading
through the method implementation.

It's even more confusing given that there's already a method
LaunchHotwordAudioVerificationApp.

The solution to this issue is to move the logic higher up.

[Anand Mistry (off Chromium), 2015/03/20 01:37:55]

Another option might be to name the function after the action that it's supposed
to handle. Like UserTriesToTurnOnAlwaysOnHotwording(), but not in so many words.

[kcarattini, 2015/03/20 04:45:01]

Renamed to OptIntoHotwording

   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.