Refactor Select-to-speak so that mouse events are forwarded to the extension.

chrome/browser/chromeos/accessibility/select_to_speak_event_handler.h

Index: chrome/browser/chromeos/accessibility/select_to_speak_event_handler.h
diff --git a/chrome/browser/chromeos/accessibility/select_to_speak_event_handler.h b/chrome/browser/chromeos/accessibility/select_to_speak_event_handler.h
index 048e2cf83d5055ca4fa458efd3a069db383b8438..6c4910be21aebd5666bcdba314e4269d67917e41 100644
--- a/chrome/browser/chromeos/accessibility/select_to_speak_event_handler.h
+++ b/chrome/browser/chromeos/accessibility/select_to_speak_event_handler.h
@@ -13,6 +13,12 @@
 
 namespace chromeos {
 
+class SelectToSpeakForwardedEventDelegateForTesting {
+ public:
+  virtual void OnForwardEventToSelectToSpeakExtension(
+      const ui::MouseEvent& event) = 0;
+};
+
 // Intercepts mouse events while the Search key is held down, and sends
 // accessibility events to the Select-to-speak extension instead.
 class SelectToSpeakEventHandler : public ui::EventHandler {
@@ -20,6 +26,11 @@ class SelectToSpeakEventHandler : public ui::EventHandler {
   SelectToSpeakEventHandler();
   ~SelectToSpeakEventHandler() override;
 
+  // For testing, call the provided callback with any events that would have
+  // been forwarded to the Select-to-speak extension instead.
+  void CaptureForwardedEventsForTesting(
+      SelectToSpeakForwardedEventDelegateForTesting* delegate);
+
  private:
   // EventHandler:
   void OnKeyEvent(ui::KeyEvent* event) override;
@@ -62,6 +73,8 @@ class SelectToSpeakEventHandler : public ui::EventHandler {
   // is pressed, and only cleared when all keys are released.
   std::set<ui::KeyboardCode> keys_pressed_together_;
 
+  SelectToSpeakForwardedEventDelegateForTesting* event_delegate_for_testing_;
+
   DISALLOW_COPY_AND_ASSIGN(SelectToSpeakEventHandler);
 };