Revert "Automatically trigger installation of high-quality speech synthesis extension."

chrome/browser/speech/tts_platform.h

Index: chrome/browser/speech/tts_platform.h
diff --git a/chrome/browser/speech/tts_platform.h b/chrome/browser/speech/tts_platform.h
index bce9693604f3273f64d6c13009f56d6bb15a7ec3..e396b7f78e748d0d55cf4868d726a9785ee3ebcf 100644
--- a/chrome/browser/speech/tts_platform.h
+++ b/chrome/browser/speech/tts_platform.h
@@ -18,6 +18,13 @@ class TtsPlatformImpl {
   // 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.