Mark DexLoaderTest.testPreviouslyLoadedFromDataDir flaky.

chrome/android/webapk/shell_apk/BUILD.gn

 # Copyright 2015 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")
 
 declare_args() {
   # The origin URL of the WebAPK. Used to generate a unique package name for
   # WebAPK. Example: "foo.com"
   webapk_manifest_package_origin = "template"
@@ skipping 60 matching lines @@
   ]
 }
 
 android_library("shell_apk_javatests") {
   testonly = true
   java_files =
       [ "javatests/src/org/chromium/webapk/shell_apk/DexLoaderTest.java" ]
   deps = [
     ":dex_loader_lib",
     "//base:base_java",
+    "//base:base_java_test_support",
     "//chrome/android/webapk/libs/common",
     "//content/public/test/android:content_java_test_support",
   ]
   srcjar_deps = [ "javatests/dex_optimizer:dex_optimizer_service_aidl" ]
 }