Add DCHECK to BrowserAccessibilityManager::Remove to detect undefined behavoir that may lead to a...

chrome/browser/accessibility/browser_accessibility_manager_unittest.cc

 // Copyright (c) 2011 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 586 matching lines @@
   // 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.id = 1002;
   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);
+  BrowserAccessibility* acc2_2 = manager->GetFromRendererID(1002);
 
   // Verify the root has not changed.
   EXPECT_EQ(root, manager->GetRoot());
 
-  // And the proper child remains.
+  // And the new child exists.
   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);
+  EXPECT_EQ(1002, acc2_2->renderer_id());
 
   // Ensure we properly cleaned up.
   manager.reset();
   ASSERT_EQ(0, CountedBrowserAccessibility::global_obj_count_);
 }