Implement support for chorded braille commands

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

 // Copyright 2014 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/brlapi_keycode_map.h"
 
 #include <stdint.h>
 
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversion_utils.h"
@@ skipping 124 matching lines @@
     case BRLAPI_KEY_CMD_BOT:
       event->command = KEY_COMMAND_BOTTOM;
       break;
     default:
       switch (code & BRLAPI_KEY_CMD_BLK_MASK) {
         case BRLAPI_KEY_CMD_ROUTE:
           event->command = KEY_COMMAND_ROUTING;
           event->display_position.reset(new int(argument));
           break;
         case BRLAPI_KEY_CMD_PASSDOTS:
-          event->command = KEY_COMMAND_DOTS;
-          event->braille_dots.reset(new int(argument & kAllDots));
+          unsigned int dots = argument & kAllDots;
+          event->braille_dots.reset(new int(dots));

[asargent_no_longer_on_chrome, 2016/11/04 19:52:35]

nit: consider using base::MakeUnique, which I think is now preferred to bare
"new" calls

event->braille_dots = base::MakeUnique<int>(dots);

+
+          // BRLAPI_DOTC represents when the braille space key is pressed.
+          if (dots && (argument & BRLAPI_DOTC))
+            event->command = KEY_COMMAND_CHORD;
+          else
+            event->command = KEY_COMMAND_DOTS;
           MapModifierFlags(code, event);
           break;
       }
   }
 }
 
 }  // namespace
 
 std::unique_ptr<KeyEvent> BrlapiKeyCodeToEvent(brlapi_keyCode_t code) {
   std::unique_ptr<KeyEvent> result(new KeyEvent);
   result->command = KEY_COMMAND_NONE;
   switch (code & BRLAPI_KEY_TYPE_MASK) {
     case BRLAPI_KEY_TYPE_SYM:
       MapKeySym(code, result.get());
       break;
     case BRLAPI_KEY_TYPE_CMD:
       MapCommand(code, result.get());
       break;
   }
   if (result->command == KEY_COMMAND_NONE)
     result.reset();
   return result;
 }
 
 }  // namespace braille_display_private
 }  // namespace api
 }  // namespace extensions