Fixing race condition on banner showing code.

chrome/browser/resources/file_manager/js/file_manager.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.
 
 /**
  * FileManager constructor.
  *
  * FileManager objects encapsulate the functionality of the file selector
  * dialogs, as well as the full screen file manager application (though the
  * latter is not yet implemented).
@@ skipping 3873 matching lines @@
     function createDiv(className, parent) {
       var div = parent.ownerDocument.createElement('div');
       div.className = className;
       parent.appendChild(div);
       return div;
     }
 
     var self = this;
 
     function showBanner(type, messageId) {
-      if (!self.dialogContainer_.hasAttribute('gdrive-welcome-style')) {
-        self.dialogContainer_.setAttribute('gdrive-welcome-style', true);
-        var style = self.document_.createElement('link');
-        style.rel = 'stylesheet';
-        style.href = 'css/gdrive_welcome.css';
-        self.document_.head.appendChild(style);
-        style.onload = function() { showBanner(type, messageId) };
-        return;
-      }
-
       self.showGDataWelcome_(type);
 
       var container = self.dialogDom_.querySelector('.gdrive-welcome.' + type);
       if (container.firstElementChild)
         return;  // Do not re-create.
 
       var wrapper = createDiv('gdrive-welcome-wrapper', container);
       createDiv('gdrive-welcome-icon', wrapper);
 
       var close = createDiv('cr-dialog-close', wrapper);
@@ skipping 42 matching lines @@
 
     var previousDirWasOnGData = false;
 
     function maybeShowBanner() {
       if (!self.isOnGData()) {
         self.showGDataWelcome_('none');
         previousDirWasOnGData = false;
         return;
       }
 
+      if (!self.dialogContainer_.hasAttribute('gdrive-welcome-style')) {
+        self.dialogContainer_.setAttribute('gdrive-welcome-style', true);
+        var style = self.document_.createElement('link');
+        style.rel = 'stylesheet';
+        style.href = 'css/gdrive_welcome.css';
+        self.document_.head.appendChild(style);
+        style.onload = function() { maybeShowBanner() };
+        return;
+      }
+
       var counter = getHeaderCounter();
 
       if (self.directoryModel_.getFileList().length == 0 && counter == 0) {
         // Only show the full page banner if the header banner was never shown.
         // Do not increment the counter.
         // The timeout below is required because sometimes another
         // 'rescan-completed' event arrives shortly with non-empty file list.
         setTimeout(function() {
           if (self.isOnGData() &&
               self.dialogContainer_.getAttribute('gdrive-welcome') != 'header')
@@ skipping 76 matching lines @@
     }
 
     var defaultActionSeparator =
         this.dialogDom_.querySelector('#default-action-separator');
 
     this.defaultActionMenuItem_.hidden = !taskItem;
     defaultActionSeparator.hidden = !taskItem;
   }
 })();