Reset margin input controls error state when error is cleared.

chrome/browser/resources/print_preview/previewarea/margin_control_container.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 cr.define('print_preview', function() {
   'use strict';
 
   /**
    * UI component used for setting custom print margins.
    * @param {!print_preview.DocumentInfo} documentInfo Document data model.
@@ skipping 413 matching lines @@
      * textbox loses focus.
      * Updates the print ticket store.
      * @param {!print_preview.MarginControl} control Updated control.
      * @private
      */
     onControlTextChange_: function(control) {
       var marginValue = this.parseValueToPts_(control.getTextboxValue());
       if (marginValue != null) {
         this.customMarginsTicketItem_.updateMargin(
             control.getOrientation(), marginValue);
+        // Enable all controls.
+        for (var o in this.controls_) {
+          this.controls_[o].setIsEnabled(true);
+        }
+        control.setIsInError(false);
       } else {
         var enableOtherControls;
         if (!control.getIsFocused()) {
           // If control no longer in focus, revert to previous valid value.
           control.setTextboxValue(
               this.serializeValueFromPts_(control.getPositionInPts()));
           control.setIsInError(false);
           enableOtherControls = true;
         } else {
           control.setIsInError(true);
           enableOtherControls = false;
         }
         // Enable other controls.
         for (var o in this.controls_) {
           if (control.getOrientation() != o) {
             this.controls_[o].setIsEnabled(enableOtherControls);
           }
         }
       }
     }
   };
 
   // Export
   return {
     MarginControlContainer: MarginControlContainer
   };
 });