PDFExtensionTest: Stop using chrome:// URL to load mock-interactions.js

chrome/test/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/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//chrome/common/features.gni")
@@ skipping 1677 matching lines @@
       "//media/test/data/",
       "//net/tools/testserver/",
       "//ppapi/tests/test_case.html",
       "//ppapi/tests/test_case.html.mock-http-headers",
       "//ppapi/tests/test_page.css",
       "//ppapi/tests/test_page.css.mock-http-headers",
       "//testing/test_env.py",
       "//third_party/accessibility-audit/axs_testing.js",
       "//third_party/chaijs/chai.js",
       "//third_party/mocha/mocha.js",
+      "//third_party/polymer/v1_0/components-chromium/iron-test-helpers/mock-interactions.js",
       "//third_party/pyftpdlib/",
       "//third_party/pywebsocket/",
       "//third_party/simplejson/",
       "//third_party/tlslite/",
       "//ui/webui/resources/js/",
       "$root_out_dir/pyproto/",
       "$root_out_dir/browser_tests.pak",
       "$root_out_dir/remoting/unittests/",
       "$root_out_dir/test_case.html",
       "$root_out_dir/test_case.html.mock-http-headers",
@@ skipping 3465 matching lines @@
 }
 
 if (is_win) {
   loadable_module("conflicts_dll") {
     testonly = true
     sources = [
       "conflicts/conflicts_dll.cc",
     ]
   }
 }