Add multiline braille support.

chrome/browser/extensions/api/braille_display_private/braille_controller.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_BRAILLE_DISPLAY_PRIVATE_BRAILLE_CONTROLLER_H_
 #define CHROME_BROWSER_EXTENSIONS_API_BRAILLE_DISPLAY_PRIVATE_BRAILLE_CONTROLLER_H_
 
 #include <memory>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/values.h"
 #include "chrome/common/extensions/api/braille_display_private.h"
 
 namespace extensions {
 namespace api {
 namespace braille_display_private {
 class BrailleObserver;
 
 // Singleton class that controls the braille display.
 class BrailleController {
  public:
   static BrailleController* GetInstance();
 
   virtual std::unique_ptr<DisplayState> GetDisplayState() = 0;
-  virtual void WriteDots(const std::vector<char>& cells) = 0;
+  virtual void WriteDots(const std::vector<std::vector<char>>& cells) = 0;
   virtual void AddObserver(BrailleObserver* observer) = 0;
   virtual void RemoveObserver(BrailleObserver* observer) = 0;
 
  protected:
   BrailleController();
   virtual ~BrailleController();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(BrailleController);
 };
 
 // Observer for events from the BrailleController
 class BrailleObserver {
  public:
   virtual void OnBrailleDisplayStateChanged(
       const DisplayState& display_state) {}
   virtual void OnBrailleKeyEvent(const KeyEvent& event) {}
 };
 
 }  // namespace braille_display_private
 }  // namespace api
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_BRAILLE_DISPLAY_PRIVATE_BRAILLE_CONTROLLER_H_