Relanding the following revisions....

webkit/tools/test_shell/test_shell.cc

Index: webkit/tools/test_shell/test_shell.cc
===================================================================
--- webkit/tools/test_shell/test_shell.cc	(revision 13602)
+++ webkit/tools/test_shell/test_shell.cc	(working copy)
@@ -7,7 +7,7 @@
 
 #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"
@@ -614,6 +614,16 @@
 
 #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;
 }