// Returns true if this platform implementation is supported and available.
virtual bool PlatformImplAvailable() = 0;
+ // Some platforms may provide a built-in TTS extension. Returns true
+ // if the extension was not previously loaded and is now loading, and
+ // false if it's already loaded or if there's no extension to load.
+ // Will call TtsController::RetrySpeakingQueuedUtterances when
+ // the extension finishes loading.
+ virtual bool LoadBuiltInTtsExtension(Profile* profile);
+
// Speak the given utterance with the given parameters if possible,
// and return true on success. Utterance will always be nonempty.
// If rate, pitch, or volume are -1.0, they will be ignored.