Add a way for JNI registrars to specify methods to be registered for tests.

testing/android/native_test_launcher.cc

Index: testing/android/native_test_launcher.cc
diff --git a/testing/android/native_test_launcher.cc b/testing/android/native_test_launcher.cc
index b88cb30313e72fe06ac03268af267c14ed3bb383..77c5ea7472a83effa055e13f82532a1fc87201f7 100644
--- a/testing/android/native_test_launcher.cc
+++ b/testing/android/native_test_launcher.cc
@@ -14,9 +14,8 @@
 #include <stdio.h>
 
 #include "base/android/jni_android.h"
+#include "base/android/jni_registrar.h"
 #include "base/android/jni_string.h"
-#include "base/android/locale_utils.h"
-#include "base/android/path_utils.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/at_exit.h"
 #include "base/command_line.h"
@@ -176,8 +175,7 @@ static void RunTests(JNIEnv* env,
       env, env->NewLocalRef(app_context));
   base::android::InitApplicationContext(scoped_context);
 
-  base::android::RegisterLocaleUtils(env);
-  base::android::RegisterPathUtils(env);
+  base::android::RegisterAllNativeMethodsForTest(env);
 
   FilePath files_dir(base::android::ConvertJavaStringToUTF8(env, jfiles_dir));
   // A few options, such "--gtest_list_tests", will just use printf directly