Make base_unittests_apk actually work

testing/android/BUILD.gn

+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/android/rules.gni")
+
+# GYP: //testing/android/native_test.gyp:native_test_native_code
+source_set("native_test_native_code") {
+  testonly = true
+  sources = [
+    "native_test_launcher.cc"
+  ]
+  deps = [
+    ":native_test_jni_headers",
+    ":native_test_util",
+    "//base",
+    "//base/test:test_support",
+    "//base/third_party/dynamic_annotations",
+    "//testing/gtest",
+  ]
+}
+
+# GYP: //testing/android/native_test.gyp:native_test_jni_headers
+generate_jni("native_test_jni_headers") {
+  sources = [
+    "java/src/org/chromium/native_test/ChromeNativeTestActivity.java",
+  ]
+  jni_package = "testing"
+}
+
+# GYP: //testing/android/native_test.gyp:native_test_util
+source_set("native_test_util") {
+  sources = [
+    "native_test_util.cc",
+    "native_test_util.h",
+  ]
+  deps = [
+    "//base"
+  ]
+}