Add a regression test for the PluginChannel::CleanUp. My earlier speculative...

chrome/test/ui/npapi_uitest.cc

 // Copyright (c) 2009 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.
 
 // windows headers
 #include <windows.h>
 #include <shellapi.h>
 #include <shlobj.h>
 #include <comutil.h>
 
 // runtime headers
 #include <stdlib.h>
 #include <string.h>
 #include <memory.h>
 
 #include <ostream>
 
 #include "base/file_util.h"
 #include "base/keyboard_codes.h"
 #include "chrome/browser/net/url_request_mock_http_job.h"
 #include "chrome/common/chrome_paths.h"
+#include "chrome/common/url_constants.h"
+#include "chrome/test/automation/browser_proxy.h"
 #include "chrome/test/automation/tab_proxy.h"
 #include "chrome/test/automation/window_proxy.h"
 #include "chrome/test/ui/npapi_test_helper.h"
 #include "net/base/net_util.h"
 
 const char kTestCompleteCookie[] = "status";
 const char kTestCompleteSuccess[] = "OK";
 const int kLongWaitTimeout = 30 * 1000;
 const int kShortWaitTimeout = 5 * 1000;
 
@@ skipping 324 matching lines @@
   SetEvent(crash_event);
   GURL url = GetTestUrl(L"npapi", L"no_hang_if_init_crashes.html");
   NavigateToURL(url);
   WaitForFinish("no_hang_if_init_crashes", "1", url,
                 kTestCompleteCookie, kTestCompleteSuccess,
                 kShortWaitTimeout);
   CloseHandle(crash_event);
 }
 
 #endif
+
+TEST_F(NPAPITester, NPObjectReleasedOnDestruction) {
+  if (UITest::in_process_renderer())
+    return;
+
+  GURL url = GetTestUrl(L"npapi", L"npobject_released_on_destruction.html");
+  NavigateToURL(url);
+
+  scoped_refptr<BrowserProxy> window_proxy(automation()->GetBrowserWindow(0));
+  window_proxy->AppendTab(GURL(chrome::kAboutBlankURL));
+
+  scoped_refptr<TabProxy> tab_proxy(window_proxy->GetTab(0));
+  tab_proxy->Close(true);
+}