Make payment manifest download/parse cross-platform

components/BUILD.gn

Index: components/BUILD.gn
diff --git a/components/BUILD.gn b/components/BUILD.gn
index dafec378ce9ffa8c8ba1f1e5fe210e638c7e2dd8..ba443f2335b11165106beedadc5062a529af2c98 100644
--- a/components/BUILD.gn
+++ b/components/BUILD.gn
@@ -205,6 +205,7 @@ test("components_unittests") {
       "//components/packed_ct_ev_whitelist:unit_tests",
       "//components/password_manager/content/browser:unit_tests",
       "//components/payments/content:unit_tests",
+      "//components/payments/content/utility:unit_tests",
       "//components/policy/core/browser:unit_tests",
       "//components/policy/core/common:unit_tests",
       "//components/precache/content:unit_tests",
@@ -247,8 +248,6 @@ test("components_unittests") {
       "//components/gcm_driver/instance_id/android:instance_id_driver_test_support_java",
       "//components/invalidation/impl",
       "//components/invalidation/impl:java",
-      "//components/payments/content/android:unit_tests",
-      "//components/payments/content/android/utility:unit_tests",
       "//components/policy/android:policy_java",
       "//components/safe_json",
       "//components/safe_json/android:safe_json_java",