Implement web speech synthesis.

content/renderer/renderer_webkitplatformsupport_impl.cc

Index: content/renderer/renderer_webkitplatformsupport_impl.cc
diff --git a/content/renderer/renderer_webkitplatformsupport_impl.cc b/content/renderer/renderer_webkitplatformsupport_impl.cc
index fa10df6407c652b0b04392097698a1161857ddc9..f21400e4480fa65835a6136d799e11241dc6cd97 100644
--- a/content/renderer/renderer_webkitplatformsupport_impl.cc
+++ b/content/renderer/renderer_webkitplatformsupport_impl.cc
@@ -855,6 +855,14 @@ WebKit::WebHyphenator* RendererWebKitPlatformSupportImpl::hyphenator() {
 
 //------------------------------------------------------------------------------
 
+WebKit::WebSpeechSynthesizer*
+RendererWebKitPlatformSupportImpl::createSpeechSynthesizer(
+    WebKit::WebSpeechSynthesizerClient* client) {
+  return GetContentClient()->renderer()->OverrideSpeechSynthesizer(client);
+}
+
+//------------------------------------------------------------------------------
+
 bool RendererWebKitPlatformSupportImpl::processMemorySizesInBytes(
     size_t* private_bytes, size_t* shared_bytes) {
   content::RenderThread::Get()->Send(