json_schema_compiler: Use std::vector<char> for binary values.

chrome/browser/extensions/api/braille_display_private/stub_braille_controller.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/stub_braille_controller.h"
 
 namespace extensions {
 namespace api {
 namespace braille_display_private {
 
 StubBrailleController::StubBrailleController() {
 }
 
 scoped_ptr<DisplayState> StubBrailleController::GetDisplayState() {
   return scoped_ptr<DisplayState>(new DisplayState);
 }
 
-void StubBrailleController::WriteDots(const std::string& cells) {
+void StubBrailleController::WriteDots(const std::vector<char>& cells) {
 }
 
 void StubBrailleController::AddObserver(BrailleObserver* observer) {
 }
 
 void StubBrailleController::RemoveObserver(BrailleObserver* observer) {
 }
 
 }  // namespace braille_display_private
 }  // namespace api
 }  // namespace extensions