Make content_shell_apk build completely

content/public/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")
 
 content_jni_gypi_values = exec_script("//build/gypi_to_gn.py",
     [ rebase_path("../../content_jni.gypi") ],
     "scope",
@@ skipping 206 matching lines @@
 }
 
 group("jni") {
   deps = [
     ":content_jni_headers",
     ":jar_jni",
   ]
 }
 
 android_library("content_javatests") {
+  testonly = true
   deps = [
     "//base:base_java",
     "//base:base_java_test_support",
     "//content/public/test/android:content_java_test_support",
     "//content/shell/android:content_shell_java",
     "//content/shell/android:content_shell_java_resources",
     "//content/shell/android:content_shell_apk_java",
     "//content/shell/android:content_shell_test_java",
     "//media/base/android:media_java",
     "//net/android:net_java",
     "//net/android:net_java_test_support",
     "//ui/android:ui_java",
     ":content_java",
   ]
 
   DEPRECATED_java_in_dir = "javatests/src"
 }
 
 
 # TODO(GYP): content_icudata