[Code health] Fix gn check for //chrome/test/media_router

TBR=estaab@chromium.org

Bug: 1158928
Change-Id: I4cebb92b0e7b6520dd057d5714dd492e7fe38c33
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2612204Reviewed-by: Evan Stade <estade@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/master@{#840888}

.gn

@@ -81,7 +81,6 @@ no_check_targets = [
   "//chrome/services/ipp_parser:*",  # 1 error
   "//chrome/services/removable_storage_writer:*",  # 1 error
   "//chrome/services/util_win:*",  # 1 error
-  "//chrome/test/media_router:*",  # 5 errors
   "//chrome/test:*",  # 2682 errors
 
   "//clank/third_party/gvr_shim:*",  # 1 error

chrome/test/BUILD.gn

@@ -442,6 +442,8 @@ static_library("test_support") {
     sources += [
       "../browser/extensions/browsertest_util.cc",
       "../browser/extensions/browsertest_util.h",
+      "../browser/extensions/extension_apitest.cc",
+      "../browser/extensions/extension_apitest.h",
       "../browser/extensions/extension_browsertest.cc",
       "../browser/extensions/extension_browsertest.h",
       "../browser/extensions/permissions_test_util.cc",
@@ -2034,8 +2036,6 @@ if (!is_android) {
         "../browser/extensions/events_apitest.cc",
         "../browser/extensions/execute_script_apitest.cc",
         "../browser/extensions/extension_action_runner_browsertest.cc",
-        "../browser/extensions/extension_apitest.cc",
-        "../browser/extensions/extension_apitest.h",
         "../browser/extensions/extension_bindings_apitest.cc",
         "../browser/extensions/extension_bookmarklet_browsertest.cc",
         "../browser/extensions/extension_browsertest_browsertest.cc",

chrome/test/media_router/BUILD.gn

@@ -26,13 +26,18 @@ source_set("browser_tests") {
   ]
   deps = [
     ":test_support",
+    "//build:chromeos_buildflags",
     "//chrome/app:generated_resources",
     "//chrome/browser",
     "//chrome/browser/media/router",
     "//chrome/browser/ui",
     "//chrome/common",
+    "//chrome/test:test_support",
     "//chrome/test:test_support_ui",
     "//components/media_router/common",
+    "//components/policy/core/browser",
+    "//components/policy/core/common:test_support",
+    "//components/sessions",
     "//content/public/browser",
     "//content/test:test_support",
     "//media:test_support",
@@ -40,6 +45,8 @@ source_set("browser_tests") {
     "//net:test_support",
     "//testing/gtest",
     "//ui/base",
+    "//ui/events:test_support",
+    "//ui/views:test_support",
     "//url",
   ]
   data_deps = [