Add unit tests for AIDL service

[ Merged from http://go/wvgerrit/150029 ]

Test: m libwvdrmengine_hal_test -j128
Test: m libwvdrmengine_hal_test WV_UNITTESTS_BUILD_TARGET=hidl -j128
Test: adb push $(OUT)/data/nativetest/libwvdrmengine_hal_test /data/nativetest/.
Test: adb shell  LD_LIBRARY_PATH=/vendor/lib64 /data/nativetest/libwvdrmengine_hal_test

Bug: 217247987
Change-Id: Ib4f22c976b8ae6c2983cb611a958ddc3a29aebdb

libwvdrmengine/test/unit/hidl/WVCreatePluginFactories_test.cpp

@@ -0,0 +1,38 @@
+//
+// Copyright 2018 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine License
+// Agreement.
+//
+
+#include "gtest/gtest.h"
+#include "WVCreatePluginFactories.h"
+
+namespace wvdrm {
+namespace hardware {
+namespace drm {
+namespace V1_4 {
+namespace widevine {
+
+using ::android::sp;
+
+using namespace android;
+
+TEST(CreatePluginFactoriesTest, CreatesDrmFactory) {
+  sp<IDrmFactory> factory(createDrmFactory());
+
+  EXPECT_NE((IDrmFactory*)NULL, factory.get()) <<
+      "createDrmFactory() returned null";
+}
+
+TEST(CreatePluginFactoriesTest, CreatesCryptoFactory) {
+  sp<ICryptoFactory> factory(createCryptoFactory());
+
+  EXPECT_NE((ICryptoFactory*)NULL, factory.get()) <<
+      "createCryptoFactory() returned null";
+}
+
+}  // namespace widevine
+}  // namespace V1_4
+}  // namespace drm
+}  // namespace hardware
+}  // namespace wvdrm