Split up ios/web:test_support.

ios/web/public/test/BUILD.gn

+# Copyright 2017 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.
+
+source_set("test_support") {
+  testonly = true
+
+  deps = [
+    "//base",
+    "//base/test:test_support",
+    "//ios/testing:ios_test_support",
+    "//ios/third_party/gcdwebserver",
+    "//ios/web:web",
+    "//ios/web:web_arc",
+    "//ios/web/public/test/fakes:test_support",
+    "//ios/web/public/test/response_providers:test_support",
+    "//ios/web/test:test_support",
+    "//testing/gtest",
+    "//ui/base",
+    "//url",
+  ]
+
+  allow_circular_includes_from = [
+    "//ios/web/public/test/response_providers:test_support",

[Eugene But (OOO till 7-30), 2017/05/23 00:15:11]

Is it possible to avoid circular dependencies by splitting BUILD files into
smaller source_sets?

[baxley, 2017/05/23 21:03:38]

These are pretty sticky. I can do the first one, by moving http_server into a
separate target.

It's harder to break the dependency circle with ios/web/test:test_support.

ios/web/test:test_support uses web_test.h and web_test_with_web_state.h, plus
some more things which are in ios/web/public/test (and used in other tests).

ios/web/public/test then relies upon a decent amount of things in ios/web/test.

It may be more reasonable to make it work when the rest of ios/web is split up.
1. Keep this as is, then clean up later (has risk of not getting done :( )
2. Split things up just to make ios/web/test and ios/web/public/test clean (this
may require another round when splitting up ios/web).
3. Change this CL to do all of ios/web (will take a lot longer).

I think I prefer number 1 or 3, but want to see what you think.

+    "//ios/web/test:test_support",
+  ]
+
+  sources = [
+    "http_server.h",
+    "http_server.mm",
+    "http_server_util.h",
+    "http_server_util.mm",
+    "js_test_util.h",
+    "js_test_util.mm",
+    "native_controller_test_util.h",
+    "native_controller_test_util.mm",
+    "navigation_test_util.h",
+    "navigation_test_util.mm",
+    "scoped_testing_web_client.h",
+    "scoped_testing_web_client.mm",
+    "test_redirect_observer.h",
+    "test_redirect_observer.mm",
+    "test_web_thread.h",
+    "test_web_thread_bundle.h",
+    "url_test_util.h",
+    "web_js_test.h",
+    "web_test.h",
+    "web_test.mm",
+    "web_test_suite.h",
+    "web_test_with_web_state.h",
+    "web_test_with_web_state.mm",
+    "web_view_interaction_test_util.h",
+    "web_view_interaction_test_util.mm",
+  ]
+}