Add browser tests for FetchEvent.request.mode/credentials in the service worker

chrome/chrome_tests.gypi

Index: chrome/chrome_tests.gypi
diff --git a/chrome/chrome_tests.gypi b/chrome/chrome_tests.gypi
index 528d89bd620d720a11c62e75dd9c246e1529339b..94fc22a8736e59f7dcdb98997cc501af08527e8e 100644
--- a/chrome/chrome_tests.gypi
+++ b/chrome/chrome_tests.gypi
@@ -2260,6 +2260,9 @@
             'browser/extensions/extension_nacl_browsertest.cc',
             'browser/nacl_host/test/gdb_debug_stub_browsertest.cc',
           ],
+          'dependencies': [
+            'test/data/nacl/nacl_test_data.gyp:pnacl_url_loader_test',
+          ],
           'conditions': [
             ['disable_nacl_untrusted==0', {
               'sources': [