Move the test template to //testing/test.gni (part 2)

printing/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/features.gni")
 import("//build/config/ui.gni")
+import("//testing/test.gni")
 if (is_mac) {
   import("//build/config/mac/mac_sdk.gni")
 }
 if (is_android) {
   import("//build/config/android/rules.gni")
 }
 
 component("printing") {
   sources = [
     "backend/print_backend.cc",
@@ skipping 223 matching lines @@
   }
 
   # GYP: //printing/printing.gyp:printing_java
   android_library("printing_java") {
     deps = [
       "//base:base_java",
     ]
     DEPRECATED_java_in_dir = "android/java/src"
   }
 }