Improvements to TestBase

This patch merges some features that were added to TestBase in
http://go/wvgerrit/92349 in the Widevine Repo. Certain parameters to
TestBase that could have been const but weren't now are. The caller to
Initialize() can now specify additional, platform-specific help text to
be displayed after the generic help text. And some missing headers were
added to test_base.h.

The Android code does not yet take advantage of any of this, but it
could in the future.

Bug: 145013234
Test: Android Unit Tests
Change-Id: I3c54532a39641622d454256b25979ad89727d43f

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();