Make contracted braille input work in more contexts.

chrome/browser/resources/chromeos/chromevox/host/chrome/braille_background.js

Index: chrome/browser/resources/chromeos/chromevox/host/chrome/braille_background.js
diff --git a/chrome/browser/resources/chromeos/chromevox/host/chrome/braille_background.js b/chrome/browser/resources/chromeos/chromevox/host/chrome/braille_background.js
index 9183a7b12fa12e2a6c775d8e9c52e5eea1f6863e..bea96b5b0061563d188f33f75d08592a333b5994 100644
--- a/chrome/browser/resources/chromeos/chromevox/host/chrome/braille_background.js
+++ b/chrome/browser/resources/chromeos/chromevox/host/chrome/braille_background.js
@@ -64,11 +64,7 @@ goog.inherits(cvox.BrailleBackground, cvox.AbstractBraille);
 
 /** @override */
 cvox.BrailleBackground.prototype.write = function(params) {
-  this.lastContentId_ = null;
-  this.lastContent_ = null;
-  this.inputHandler_.onDisplayContentChanged(params.text);
-  this.displayManager_.setContent(
-      params, this.inputHandler_.getExpansionType());
+  this.setContent_(params, null);
 };
 
 
@@ -94,16 +90,31 @@ cvox.BrailleBackground.prototype.getTranslatorManager = function() {
  */
 cvox.BrailleBackground.prototype.onBrailleMessage = function(msg) {
   if (msg['action'] == 'write') {
-    this.lastContentId_ = msg['contentId'];
-    this.lastContent_ = cvox.NavBraille.fromJson(msg['params']);
-    this.inputHandler_.onDisplayContentChanged(this.lastContent_.text);
-    this.displayManager_.setContent(
-        this.lastContent_, this.inputHandler_.getExpansionType());
+    this.setContent_(cvox.NavBraille.fromJson(msg['params']),
+                     msg['contentId']);
   }
 };
 
 
 /**
+ * @param {!cvox.NavBraille} newContent
+ * @param {?string} newContentId
+ * @private
+ */
+cvox.BrailleBackground.prototype.setContent_ = function(
+    newContent, newContentId) {
+  var updateContent = function() {
+    this.lastContent_ = newContentId ? newContent : null;
+    this.lastContentId_ = newContentId;
+    this.displayManager_.setContent(
+        newContent, this.inputHandler_.getExpansionType());
+  }.bind(this);
+  this.inputHandler_.onDisplayContentChanged(newContent.text, updateContent);
+  updateContent();
+};
+
+
+/**
  * Handles braille key events by dispatching either to the input handler or
  * a content script.
  * @param {!cvox.BrailleKeyEvent} brailleEvt The event.