Merge to m56: 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..2f3505ff4d343bc2242b372446e1556c182eabdd 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 {Set} @private */
+  this.eatenKeyDowns_ = new Set();
+
   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.eatenKeyDowns_.add(evt.keyCode);
     }
     Output.forceModeForNextSpeechUtterance(cvox.QueueMode.FLUSH);
     return false;
@@ -59,6 +63,13 @@ BackgroundKeyboardHandler.prototype = {
         this.passThroughKeyUpCount_++;
       }
     }
+
+    if (this.eatenKeyDowns_.has(evt.keyCode)) {
+      evt.preventDefault();
+      evt.stopPropagation();
+      this.eatenKeyDowns_.delete(evt.keyCode);
+    }
+
     return false;
   },