Implement support for chorded braille commands

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

Index: chrome/browser/extensions/api/braille_display_private/brlapi_keycode_map.cc
diff --git a/chrome/browser/extensions/api/braille_display_private/brlapi_keycode_map.cc b/chrome/browser/extensions/api/braille_display_private/brlapi_keycode_map.cc
index 1e8a9530699e84a6c938ed339f040f22b41ba2d7..aa4e913a4fc0b55f9b735de4676fbdb8a76e906f 100644
--- a/chrome/browser/extensions/api/braille_display_private/brlapi_keycode_map.cc
+++ b/chrome/browser/extensions/api/braille_display_private/brlapi_keycode_map.cc
@@ -142,8 +142,14 @@ void MapCommand(brlapi_keyCode_t code, KeyEvent* event) {
           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;
       }