Add assertion to EmbeddedTestServer creation method

net/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/config.gni")
 import("//build/config/android/rules.gni")
 
 android_library("net_java") {
   java_files = [
     "java/src/org/chromium/net/AndroidCellularSignalStrength.java",
@@ skipping 40 matching lines @@
     "../test/android/javatests/src/org/chromium/net/test/EmbeddedTestServerService.java",
     "../test/android/javatests/src/org/chromium/net/test/util/CertTestUtil.java",
     "../test/android/javatests/src/org/chromium/net/test/util/NetworkChangeNotifierTestUtil.java",
     "../test/android/javatests/src/org/chromium/net/test/util/TestWebServer.java",
   ]
   deps = [
     ":net_java",
     "//base:base_java",
     "//base:base_java_test_support",
     "//third_party/android_tools:android_support_annotations_java",
+    "//third_party/junit",
   ]
   srcjar_deps = [
     ":embedded_test_server_aidl",
     ":net_java_test_support_enums_srcjar",
   ]
 }
 
 source_set("java_test_native_support") {
   testonly = true
   sources = [
@@ skipping 93 matching lines @@
   java_files =
       [ "junit/src/org/chromium/net/HttpNegotiateAuthenticatorTest.java" ]
   deps = [
     ":net_java",
     "//base:base_java",
     "//base:base_java_test_support",
     "//third_party/hamcrest:hamcrest_java",
   ]
   srcjar_deps = [ "//base:base_build_config_gen" ]
 }