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

chrome/test/perf/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("//testing/rules.gni")
+
 # This test appears to be a legacy target consisting of files not yet moved
 # elsewhere.
 test("perf") {
   output_name = "perf_tests"
 
   sources = [
     "perftests.cc",
     "url_parse_perftest.cc",
     "//content/browser/net/sqlite_persistent_cookie_store_perftest.cc",
   ]
 
   deps = [
     "//base",
     "//base/allocator",
     "//base/test:test_support",
     "//content",
     "//net",
     "//testing/gtest",
     "//url",
   ]
 }