Implement web speech synthesis.

content/renderer/render_view_impl.h

Index: content/renderer/render_view_impl.h
diff --git a/content/renderer/render_view_impl.h b/content/renderer/render_view_impl.h
index b8614ed39f5945e393b9b6181f5d3cd7acf9fe5b..c45ae53faf07281d02e9a6d8c5b8c280a5b1b78f 100644
--- a/content/renderer/render_view_impl.h
+++ b/content/renderer/render_view_impl.h
@@ -168,6 +168,7 @@ class RendererPpapiHost;
 class RendererWebColorChooserImpl;
 class RenderWidgetFullscreenPepper;
 class SpeechRecognitionDispatcher;
+class TtsDispatcher;
 class WebPluginDelegateProxy;
 struct CustomContextMenuContext;
 struct FileChooserParams;
@@ -511,6 +512,7 @@ class CONTENT_EXPORT RenderViewImpl
   virtual WebKit::WebSpeechInputController* speechInputController(
       WebKit::WebSpeechInputListener* listener);
   virtual WebKit::WebSpeechRecognizer* speechRecognizer();
+  virtual WebKit::WebSpeechSynthesis* speechSynthesis();
   virtual WebKit::WebDeviceOrientationClient* deviceOrientationClient();
   virtual void zoomLimitsChanged(double minimum_level, double maximum_level);
   virtual void zoomLevelChanged();
@@ -1444,6 +1446,10 @@ class CONTENT_EXPORT RenderViewImpl
   // initialized.
   SpeechRecognitionDispatcher* speech_recognition_dispatcher_;
 
+  // The speech synthesis dispatcher attached to this view, lazily
+  // initialized.
+  TtsDispatcher* tts_dispatcher_;
+
   // Device orientation dispatcher attached to this view; lazily initialized.
   DeviceOrientationDispatcher* device_orientation_dispatcher_;