Fix a few lingering bugs in BrowserAccessibilityManager and BrowserAccessibilityCocoa.

chrome/browser/accessibility/browser_accessibility_manager_unittest.cc

 // Copyright (c) 2010 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.
 
 #include "base/string16.h"
 #include "base/utf_string_conversions.h"
 #include "content/browser/accessibility/browser_accessibility.h"
 #include "content/browser/accessibility/browser_accessibility_manager.h"
 #include "content/common/view_messages.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 533 matching lines @@
   msg->acc_obj = tree2_1;
   manager->OnAccessibilityNotifications(params);
 
   // There should be 4 objects now.
   EXPECT_EQ(4, CountedBrowserAccessibility::global_obj_count_);
 
   // Delete the manager and make sure all memory is cleaned up.
   delete manager;
   ASSERT_EQ(0, CountedBrowserAccessibility::global_obj_count_);
 }
+
+TEST(BrowserAccessibilityManagerTest, TestCreateEmptyDocument) {
+  // Try creating an empty document with busy state.
+  BrowserAccessibilityManager* manager =
+      BrowserAccessibilityManager::CreateEmptyDocument(
+          NULL,
+          WebAccessibility::STATE_BUSY,
+          NULL,
+          new CountedBrowserAccessibilityFactory());
+
+// Verify the root is as we expect by default.
+  BrowserAccessibility* root = manager->GetRoot();
+  EXPECT_EQ(1000, root->renderer_id());
+  EXPECT_EQ(WebAccessibility::ROLE_WEB_AREA, root->role());
+  EXPECT_EQ(WebAccessibility::STATE_BUSY, root->state());
+
+  // Tree with a child textfield.
+  WebAccessibility tree1_1;
+  tree1_1.id = 1000;
+  tree1_1.role = WebAccessibility::ROLE_WEB_AREA;
+
+  WebAccessibility tree1_2;
+  tree1_2.id = 1001;
+  tree1_2.role = WebAccessibility::ROLE_TEXT_FIELD;
+
+  tree1_1.children.push_back(tree1_2);
+
+  // Process a load complete.
+  std::vector<ViewHostMsg_AccessibilityNotification_Params> params;
+  params.push_back(ViewHostMsg_AccessibilityNotification_Params());
+  ViewHostMsg_AccessibilityNotification_Params* msg = &params[0];
+  msg->notification_type = ViewHostMsg_AccessibilityNotification_Type::
+      NOTIFICATION_TYPE_LOAD_COMPLETE;
+  msg->acc_obj = tree1_1;
+
+  manager->OnAccessibilityNotifications(params);
+
+  // Save for later comparison.
+  BrowserAccessibility* acc1_2 = manager->GetFromRendererID(1001);
+
+  // Verify the root has not changed.
+  EXPECT_EQ(root, manager->GetRoot());
+
+  // And the proper child remains.
+  EXPECT_EQ(WebAccessibility::ROLE_TEXT_FIELD, acc1_2->role());
+  EXPECT_EQ(1001, acc1_2->renderer_id());
+
+  // Tree with a child button.
+  WebAccessibility tree2_1;
+  tree2_1.id = 1000;
+  tree2_1.role = WebAccessibility::ROLE_WEB_AREA;
+
+  WebAccessibility tree2_2;
+  tree2_2.id = 1001;
+  tree2_2.role = WebAccessibility::ROLE_BUTTON;
+
+  tree2_1.children.push_back(tree2_2);
+
+  msg->acc_obj = tree2_1;
+
+  // Fire another load complete.
+  manager->OnAccessibilityNotifications(params);
+
+  BrowserAccessibility* acc2_2 = manager->GetFromRendererID(1001);
+
+  // Verify the root has not changed.
+  EXPECT_EQ(root, manager->GetRoot());
+
+  // And the proper child remains.
+  EXPECT_EQ(WebAccessibility::ROLE_BUTTON, acc2_2->role());
+  EXPECT_EQ(1001, acc2_2->renderer_id());
+
+  // Verify we don't reuse objects that have changed roles.
+  EXPECT_NE(acc1_2, acc2_2);
+}