Don't autostart Chromevox in tests when a braille display is connected.

chrome/browser/extensions/api/braille_display_private/braille_controller_stub.cc

 // Copyright 2013 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 "chrome/browser/extensions/api/braille_display_private/braille_controller.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
+#include "chrome/browser/extensions/api/braille_display_private/stub_braille_controller.h"
 #include "chrome/common/extensions/api/braille_display_private.h"
 
 namespace extensions {
 namespace api {
 namespace braille_display_private {
 
-// Stub implementation of BrailleController for use when brlapi is not
-// enabled.
-class BrailleControllerImpl : public BrailleController {
- public:
-  static BrailleControllerImpl* GetInstance();
-  scoped_ptr<DisplayState> GetDisplayState() override;
-  void WriteDots(const std::vector<char>& cells) override;
-  void AddObserver(BrailleObserver* observer) override;
-  void RemoveObserver(BrailleObserver* observer) override;
-
- private:
-  BrailleControllerImpl();
-  ~BrailleControllerImpl() override;
-  friend struct base::DefaultSingletonTraits<BrailleControllerImpl>;
-  DISALLOW_COPY_AND_ASSIGN(BrailleControllerImpl);
-};
-
 BrailleController::BrailleController() {
 }
 
 BrailleController::~BrailleController() {
 }
 
 // static
 BrailleController* BrailleController::GetInstance() {
-  return BrailleControllerImpl::GetInstance();
-}
-
-BrailleControllerImpl::BrailleControllerImpl() {
-}
-
-BrailleControllerImpl::~BrailleControllerImpl() {
-}
-
-// static
-BrailleControllerImpl* BrailleControllerImpl::GetInstance() {
-  return base::Singleton<
-      BrailleControllerImpl,
-      base::LeakySingletonTraits<BrailleControllerImpl>>::get();
-}
-
-scoped_ptr<DisplayState> BrailleControllerImpl::GetDisplayState() {
-  return scoped_ptr<DisplayState>(new DisplayState()).Pass();
-}
-
-void BrailleControllerImpl::WriteDots(const std::vector<char>& cells) {
-}
-
-void BrailleControllerImpl::AddObserver(BrailleObserver* observer) {
-}
-
-void BrailleControllerImpl::RemoveObserver(BrailleObserver* observer) {
+  return StubBrailleController::GetInstance();
 }
 
 }  // namespace braille_display_private
 }  // namespace api
 }  // namespace extensions