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

chrome/browser/search/hotword_service.h

 // 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.
 
 #ifndef CHROME_BROWSER_SEARCH_HOTWORD_SERVICE_H_
 #define CHROME_BROWSER_SEARCH_HOTWORD_SERVICE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 119 matching lines @@
   // Sets the pref value of the previous language.
   void SetPreviousLanguagePref();
 
   // Returns the current error message id. A value of 0 indicates
   // no error.
   int error_message() { return error_message_; }
 
   // 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.
   void StartTraining();
   void FinalizeSpeakerModel();
   void StopTraining();
   void NotifyHotwordTriggered();
 
   // Returns true if speaker training is currently in progress.
   bool IsTraining();
@@ skipping 58 matching lines @@
 
   // The WeakPtrFactory should be the last member, so the weak pointer
   // gets invalidated before the destructors for other members run,
   // to avoid callbacks into a half-destroyed object.
   base::WeakPtrFactory<HotwordService> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HotwordService);
 };
 
 #endif  // CHROME_BROWSER_SEARCH_HOTWORD_SERVICE_H_