MC-3311: Bug fixing for MC-1416

Localize open_browser_callback to prevent observable from being called for every instance

Author: danmooney2

lib/web/mage/adminhtml/wysiwyg/tiny_mce/tinymce4Adapter.js

@@ -48,7 +48,6 @@ define([
             varienGlobalEvents.attachEventHandler('tinymceSetContent', this.updateTextArea);
             varienGlobalEvents.attachEventHandler('tinymceSaveContent', this.saveContent);
             varienGlobalEvents.attachEventHandler('tinymceUndo', this.onUndo);
-            varienGlobalEvents.attachEventHandler('open_browser_callback', this.openFileBrowser);
 
             if (typeof tinyMceEditors === 'undefined') {
                 window.tinyMceEditors = $H({});
@@ -117,6 +116,7 @@ define([
             jQuery.when.apply(jQuery, deferreds).done(function () {
                 tinyMCE4.init(settings);
                 this.getPluginButtons().hide();
+                this.eventBus.attachEventHandler('open_browser_callback', this.openFileBrowser);
             }.bind(this));
         },
 
@@ -264,12 +264,15 @@ define([
                  * @param {*} w
                  */
                 settings['file_browser_callback'] = function (fieldName, url, objectType, w) {
-                    varienGlobalEvents.fireEvent('open_browser_callback', {
+                    var payload = {
                         win: w,
                         type: objectType,
                         field: fieldName
-                    });
-                };
+                    };
+
+                    varienGlobalEvents.fireEvent('open_browser_callback', payload);
+                    this.eventBus.fireEvent('open_browser_callback', payload);
+                }.bind(this);
             }
 
             if (this.config.width) {