Headless: Remove obsolete Mojo code and some other obsolete APIs

headless/BUILD.gn

Index: headless/BUILD.gn
diff --git a/headless/BUILD.gn b/headless/BUILD.gn
index 86ace31e99f38c90e934f1e355bcda606a82e561..8298ad60a9c73e03935fab1073633202c68b25a0 100644
--- a/headless/BUILD.gn
+++ b/headless/BUILD.gn
@@ -409,38 +409,6 @@ test("headless_unittests") {
   ]
 }
 
-mojom("embedder_mojo_for_testing") {
-  sources = [
-    "lib/embedder_test.mojom",
-  ]
-}
-
-grit("headless_browsertest_resources_grit") {
-  source = "lib/headless_browsertest_resources.grd"
-  outputs = [
-    "grit/headless_browsertest_resources.h",
-    "$root_gen_dir/headless/headless_browsertest_resources.pak",
-  ]
-  grit_flags = [
-    "-E",
-    "mojom_root=" + rebase_path(root_gen_dir),
-  ]
-  deps = [
-    ":embedder_mojo_for_testing__generator",
-  ]
-  resource_ids = "lib/headless_browsertest_resource_ids"
-}
-
-repack("headless_browser_tests_pak") {
-  sources = [
-    "$root_gen_dir/headless/headless_browsertest_resources.pak",
-  ]
-  output = "$root_out_dir/headless_browser_tests.pak"
-  deps = [
-    ":headless_browsertest_resources_grit",
-  ]
-}
-
 if (is_mac) {
   copy("mac_helpers") {
     sources = [
@@ -459,7 +427,6 @@ if (is_mac) {
 
 test("headless_browsertests") {
   sources = [
-    "lib/embedder_mojo_browsertest.cc",
     "lib/frame_id_browsertest.cc",
     "lib/headless_browser_browsertest.cc",
     "lib/headless_browser_context_browsertest.cc",
@@ -494,8 +461,6 @@ test("headless_browsertests") {
   defines = [ "HAS_OUT_OF_PROC_TEST_RUNNER" ]
 
   deps = [
-    ":embedder_mojo_for_testing",
-    ":headless_browser_tests_pak",
     ":headless_lib",
     "//base",
     "//content/test:test_support",