Add DeletePluginInDeallocate UI test.

chrome/test/ui/npapi_test_helper.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 "chrome/test/ui/npapi_test_helper.h"
 
 #include "base/file_util.h"
 #include "base/test/test_file_util.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_switches.h"
 #include "webkit/plugins/npapi/plugin_list.h"
 
 namespace npapi_test {
 const char kTestCompleteCookie[] = "status";
 const char kTestCompleteSuccess[] = "OK";
 }  // namespace npapi_test.
 
 NPAPITesterBase::NPAPITesterBase() {
+  // Some NPAPI tests schedule garbage collection to force object tear-down.
+  launch_arguments_.AppendSwitchASCII(switches::kJavaScriptFlags,
+                                      "--expose_gc");
 }
 
 void NPAPITesterBase::SetUp() {
 #if defined(OS_MACOSX)
   // The plugins directory isn't read by default on the Mac, so it needs to be
   // explicitly registered.
   launch_arguments_.AppendSwitchPath(switches::kExtraPluginDir,
                                      GetPluginsDirectory());
 #endif
 
   UITest::SetUp();
 }
 
 FilePath NPAPITesterBase::GetPluginsDirectory() {
   FilePath plugins_directory = browser_directory_.AppendASCII("plugins");
   return plugins_directory;
 }
 
 // NPAPIVisiblePluginTester members.
 void NPAPIVisiblePluginTester::SetUp() {
   show_window_ = true;
   NPAPITesterBase::SetUp();
 }
 
 // NPAPIIncognitoTester members.
 void NPAPIIncognitoTester::SetUp() {
   launch_arguments_.AppendSwitch(switches::kIncognito);
   NPAPITesterBase::SetUp();
 }