diff --git a/libwvdrmengine/cdm/core/test/test_base.cpp b/libwvdrmengine/cdm/core/test/test_base.cpp
index 657184ac..a2ab575a 100644
--- a/libwvdrmengine/cdm/core/test/test_base.cpp
+++ b/libwvdrmengine/cdm/core/test/test_base.cpp
@@ -32,7 +32,7 @@ using wvcdm::metrics::EngineMetrics;
 
 namespace wvcdm {
 namespace {
-void show_menu(char* prog_name) {
+void show_menu(const char* prog_name, const std::string& extra_help_text) {
   std::cout << std::endl;
   std::cout << "usage: " << prog_name << " [options]" << std::endl << std::endl;
   std::cout << "  enclose multiple arguments in '' when using adb shell"
@@ -97,6 +97,8 @@ void show_menu(char* prog_name) {
       << "    configure the provisioning server url, please include http[s]"
       << "    in the url" << std::endl
       << std::endl;
+
+  std::cout << extra_help_text << std::endl;
 }
 
 /*
@@ -393,7 +395,8 @@ void WvCdmTestBase::EnsureProvisioned() {
   ASSERT_EQ(NO_ERROR, cdm_engine.CloseSession(session_id));
 }
 
-bool WvCdmTestBase::Initialize(int argc, char** argv) {
+bool WvCdmTestBase::Initialize(int argc, const char* const argv[],
+                               const std::string& extra_help_text) {
   Properties::Init();
   bool is_cast_receiver = false;
   bool force_load_test_keybox = false;  // TODO(fredgc): obsolete. remove.
@@ -454,7 +457,7 @@ bool WvCdmTestBase::Initialize(int argc, char** argv) {
   }
 
   if (show_usage) {
-    show_menu(argv[0]);
+    show_menu(argv[0], extra_help_text);
     return false;
   }
 
diff --git a/libwvdrmengine/cdm/core/test/test_base.h b/libwvdrmengine/cdm/core/test/test_base.h
index ca2a2f5a..dd0a84e5 100644
--- a/libwvdrmengine/cdm/core/test/test_base.h
+++ b/libwvdrmengine/cdm/core/test/test_base.h
@@ -5,6 +5,9 @@
 #ifndef WVCDM_CORE_TEST_BASE_H_
 #define WVCDM_CORE_TEST_BASE_H_
 
+#include <string>
+#include <vector>
+
 #include <gtest/gtest.h>
 
 #include "cdm_engine.h"
@@ -29,8 +32,13 @@ class WvCdmTestBase : public ::testing::Test {
 
   // Returns true if the test program should continue, if false, the caller
   // should exit.  This should be called by main() to allow the user to pass in
-  // command line switches.
-  static bool Initialize(int argc, char **argv);
+  // command line switches.  The |extra_help_text| parameter can be used to
+  // append platform-specific information to the usage information printed when
+  // invalid flags are detected. For instance, a platform might add information
+  // about platform-specific flags that were already parsed before calling
+  // Initialize().
+  static bool Initialize(int argc, const char* const argv[],
+                         const std::string& extra_help_text = std::string());
   // Install a test keybox, if appropriate.
   static void InstallTestRootOfTrust();