Move initialization of text edit handler

Correct sequence on focus:
- focus changes
- range updates
- create text edit handler if needed

The last check (to create text edit handler) depends on the ChromeVox range
having previously been updated.

character doesn't get read prior to patch and does get read post patch.

Test: manually tab to the question text field in Classroom. Verify that initial
Bug: 785283
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: Id0a4bd8ad17fc2895b802961e739db8e415b9026
Reviewed-on: https://chromium-review.googlesource.com/777900
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517903}

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

@@ -302,8 +302,6 @@ DesktopAutomationHandler.prototype = {
     if (node.role == RoleType.EMBEDDED_OBJECT || node.role == RoleType.WEB_VIEW)
       return;
 
-    this.createTextEditHandlerIfNeeded_(evt.target);
-
     // Category flush speech triggered by events with no source. This includes
     // views.
     if (evt.eventFrom == '')
@@ -329,6 +327,9 @@ DesktopAutomationHandler.prototype = {
     }
     var event = new CustomAutomationEvent(EventType.FOCUS, node, evt.eventFrom);
     this.onEventDefault(event);
+
+    // Refresh the handler, if needed, now that ChromeVox focus is up to date.
+    this.createTextEditHandlerIfNeeded_(node);
   },
 
   /**