[Mac]: Enable speech sub-menu under the edit menu and pipe it through to the renderer.

content/browser/renderer_host/render_widget_host_mac.cc

 // Copyright (c) 2012 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.
 
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "content/port/browser/render_widget_host_view_port.h"
 
 using content::RenderWidgetHostImpl;
 
@@ skipping 56 matching lines @@
   if (view_) {
     // This code path could be updated to implement flow control for
     // updating of accelerated plugins as well. However, if we add support
     // for composited plugins then this is not necessary.
     GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params params;
     params.window = window;
     params.surface_handle = surface_handle;
     view_->AcceleratedSurfaceBuffersSwapped(params, 0);
   }
 }
+
+void RenderWidgetHostImpl::OnMsgSpeakText(const string16& text) {
+  if (view_)
+    view_->SpeakText(text);
+}