Relanding the following revisions....

webkit/tools/test_shell/test_shell.cc

 // Copyright (c) 2006-2008 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 "v8_proxy.h"
 #undef LOG
 
 #include "webkit/tools/test_shell/test_shell.h"
 
-
+#include "base/base_paths.h"
 #include "base/command_line.h"
 #include "base/debug_on_start.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/gfx/png_encoder.h"
 #include "base/gfx/size.h"
 #include "base/icu_util.h"
 #if defined(OS_MACOSX)
 #include "base/mac_util.h"
 #endif
@@ skipping 586 matching lines @@
   return true;
 }
 #endif
 
 bool GetPluginFinderURL(std::string* plugin_finder_url) {
   return false;
 }
 
 #if !defined(LINUX2)
 bool IsDefaultPluginEnabled() {
+#if defined(OS_WIN)
+  FilePath exe_path;
+
+  if (PathService::Get(base::FILE_EXE, &exe_path)) {
+    std::wstring exe_name = file_util::GetFilenameFromPath(
+        exe_path.ToWStringHack());
+    if (StartsWith(exe_name, L"test_shell_tests", false))
+      return true;
+  }
+#endif  // OS_WIN
   return false;
 }
 
 std::wstring GetWebKitLocale() {
   return L"en-US";
 }
 #endif
 
 }  // namespace webkit_glue