Long press menu (shift+f6) to toggle spoken feedback.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 5a9f0242e9b7a19be92fd8b60451c18632342615..afa92345e566d4c67261d62f27d6e8b818b143ce 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -11,6 +11,7 @@
 #include "ash/accelerators/accelerator_filter.h"
 #include "ash/accelerators/focus_manager_factory.h"
 #include "ash/accelerators/nested_dispatcher_controller.h"
+#include "ash/accelerators/spoken_feedback_toggler.h"
 #include "ash/ash_switches.h"
 #include "ash/autoclick/autoclick_controller.h"
 #include "ash/caps_lock_delegate.h"
@@ -620,8 +621,11 @@ Shell::~Shell() {
   if (window_modality_controller_)
     window_modality_controller_.reset();
 #if defined(OS_CHROMEOS) && defined(USE_X11)
-  RemovePreTargetHandler(magnifier_key_scroller_.get());
-  magnifier_key_scroller_.reset();
+  RemovePreTargetHandler(magnifier_key_scroll_handler_.get());
+  magnifier_key_scroll_handler_.reset();
+
+  RemovePreTargetHandler(speech_feedback_handler_.get());
+  speech_feedback_handler_.reset();
 #endif
   RemovePreTargetHandler(event_rewriter_filter_.get());
   RemovePreTargetHandler(user_activity_detector_.get());
@@ -829,8 +833,10 @@ void Shell::Init() {
   accelerator_controller_.reset(new AcceleratorController);
 
 #if defined(OS_CHROMEOS) && defined(USE_X11)
-  magnifier_key_scroller_.reset(new MagnifierKeyScroller);
-  AddPreTargetHandler(magnifier_key_scroller_.get());
+  magnifier_key_scroll_handler_.reset(MagnifierKeyScroller::CreateHandler());
+  AddPreTargetHandler(magnifier_key_scroll_handler_.get());
+  speech_feedback_handler_.reset(SpokenFeedbackToggler::CreateHandler());
+  AddPreTargetHandler(speech_feedback_handler_.get());
 #endif
 
   // The order in which event filters are added is significant.