Ensure spoken feedback keyboard hooks prevent re-injection of key up events

chrome/browser/resources/chromeos/chromevox/cvox2/background/keyboard_handler.js

Index: chrome/browser/resources/chromeos/chromevox/cvox2/background/keyboard_handler.js
diff --git a/chrome/browser/resources/chromeos/chromevox/cvox2/background/keyboard_handler.js b/chrome/browser/resources/chromeos/chromevox/cvox2/background/keyboard_handler.js
index 8d4990f33f33e159adff7918c48b22f46f78dc87..bed8ddb181fce284e0b511239c72bb475e5c7dc7 100644
--- a/chrome/browser/resources/chromeos/chromevox/cvox2/background/keyboard_handler.js
+++ b/chrome/browser/resources/chromeos/chromevox/cvox2/background/keyboard_handler.js
@@ -18,6 +18,9 @@ BackgroundKeyboardHandler = function() {
   /** @type {number} @private */
   this.passThroughKeyUpCount_ = 0;
 
+  /** @type {Array<number>} @private */
+  this.preventedKeys_ = [];
+
   document.addEventListener('keydown', this.onKeyDown.bind(this), false);
   document.addEventListener('keyup', this.onKeyUp.bind(this), false);
 };
@@ -38,6 +41,7 @@ BackgroundKeyboardHandler.prototype = {
         !cvox.ChromeVoxKbHandler.basicKeyDownActionsListener(evt)) {
       evt.preventDefault();
       evt.stopPropagation();
+      this.preventedKeys_.push(evt.keyCode);
     }
     Output.forceModeForNextSpeechUtterance(cvox.QueueMode.FLUSH);
     return false;
@@ -59,6 +63,22 @@ BackgroundKeyboardHandler.prototype = {
         this.passThroughKeyUpCount_++;
       }
     }
+
+    var wasDown = false;
+    var updatedKeys = [];
+    for (var i = 0; i < this.preventedKeys_.length; i++) {

[dmazzoni, 2016/12/06 07:25:22]

If you make preventedKeys_ a Set(), I think you can replace all of this code
with just this:

if (this.preventedKeys_.has(evt.keyCode)) {
  this.preventedKeys_.delete(evt.keyCode);
  evt.preventDefault();
  evt.stopPropagation();
}

[David Tseng, 2016/12/06 16:55:53]

Sure. Was storing the entire event before. Changed to use a set.

+      var otherKeyCode = this.preventedKeys_[i];
+      if (otherKeyCode == evt.keyCode)
+        wasDown = true;
+      else
+        updatedKeys.push(otherKeyCode);
+    }
+    this.preventedKeys_ = updatedKeys;
+
+    if (wasDown) {
+      evt.preventDefault();
+      evt.stopPropagation();
+    }
     return false;
   },