Scope ChromeVox navigation within content editables only when it has content

Bug: 849726
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: Ie758887410ce95bd4650e46c31a3d81c9b450930
Reviewed-on: https://chromium-review.googlesource.com/1087499Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#564915}

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

@@ -395,9 +395,10 @@ AutomationPredicate.root = function(node) {
  * @param {AutomationNode} node
  * @return {boolean}
  */
-AutomationPredicate.editableRoot = function(node) {
+AutomationPredicate.rootOrEditableRoot = function(node) {
   return AutomationPredicate.root(node) ||
-      node.state.richlyEditable && node.state.focused;
+      (node.state.richlyEditable && node.state.focused &&
+       node.children.length > 0);
 };
 
 /**

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

@@ -250,7 +250,7 @@ CommandHandler.onCommand = function(command) {
   var dir = Dir.FORWARD;
   var pred = null;
   var predErrorMsg = undefined;
-  var rootPred = AutomationPredicate.editableRoot;
+  var rootPred = AutomationPredicate.rootOrEditableRoot;
   var shouldWrap = true;
   var speechProps = {};
   var skipSync = false;
@@ -756,7 +756,7 @@ CommandHandler.onCommand = function(command) {
         }
 
         var root = bound;
-        while (root && !AutomationPredicate.editableRoot(root))
+        while (root && !AutomationPredicate.rootOrEditableRoot(root))
           root = root.parent;
 
         if (!root)