Send backspace to ChromeVox from Braille IME.

chrome/browser/resources/chromeos/braille_ime/externs.js

Index: chrome/browser/resources/chromeos/braille_ime/externs.js
diff --git a/chrome/browser/resources/chromeos/braille_ime/externs.js b/chrome/browser/resources/chromeos/braille_ime/externs.js
index 1ca953473ee02be6198bdd1eb5d2d565ef0430c1..5f0d22a455f6571afb315bd5039319f1a50c77d8 100644
--- a/chrome/browser/resources/chromeos/braille_ime/externs.js
+++ b/chrome/browser/resources/chromeos/braille_ime/externs.js
@@ -42,6 +42,12 @@ chrome.input.ime.commitText = function(parameters, opt_callback) {};
 chrome.input.ime.deleteSurroundingText = function(parameters, opt_callback) {};
 
 /**
+ * @param {string} requestId
+ * @param {boolean} response
+ */
+chrome.input.ime.keyEventHandled = function(requestId, response) {};
+
+/**
  * @param {{engineID: string, items: Array.<chrome.input.ime.MenuItem>}}
  *     parameters
  * @param {function()=} opt_callback
@@ -144,6 +150,9 @@ ChromeKeyboardEvent.prototype.shiftKey;
 /** @type {boolean} */
 ChromeKeyboardEvent.prototype.capsLock;
 
+/** @type {string} */
+ChromeKeyboardEvent.prototype.requestId;
+
 /**
  * @constructor
  */